Instructions Manual Power LV Active Filter PQFT · 1. Safety instructions These safety instructions...

Instructions Manual PowerIT

LV Active FilterPQFT

PQFT Instructions Manual

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Table of contents

1. SAFETY INSTRUCTIONS................................................................................................................ 5

2. UPON RECEPTION......................................................................................................................... 6

2.1. DELIVERY INSPECTION............................................................................................................... 62.2. IDENTIFICATION TAG.................................................................................................................. 62.3. STORAGE................................................................................................................................ 62.4. LONG STORAGE PERIOD AND REFORMING ..................................................................................... 6

3. PQFT PRINCIPLE AND CHARACTERISTICS .................................................................................. 7

3.1. REASONS FOR LIMITING HARMONICS ............................................................................................ 73.2. GENERAL PRINCIPLE OF ACTIVE FILTERING.................................................................................... 93.3. THE ABB ACTIVE FILTER: THE PQFT. ........................................................................................103.4. THE PQFT: PERFORMANCES.....................................................................................................12

3.4.1. Filtering.....................................................................................................................123.4.2. Reactive power..........................................................................................................133.4.3. EMC.........................................................................................................................13

4. COMPONENTS DESCRIPTION AND IDENTIFICATION ..................................................................14

4.1. COMPONENTS DESCRIPTION......................................................................................................144.1.1. PQF current generator. ..............................................................................................144.1.2. The control................................................................................................................16

4.2. COMPONENTS IDENTIFICATION...................................................................................................16

5. MECHANICAL INSTALLATION ......................................................................................................22

5.1. GENERALITIES ........................................................................................................................225.2. IP00 PLATE............................................................................................................................24

5.2.1. Mounting of the plate.................................................................................................245.2.2. Master cubicle door accessories .................................................................................255.2.3. Slave cubicle door .....................................................................................................25

6. ELECTRICAL INSTALLATION .......................................................................................................26

6.1. OVERVOLTAGE........................................................................................................................266.2. POWER CABLES AND EXTERNAL PROTECTION...............................................................................266.3. CURRENT TRANSFORMERS/CONTROL CABLES SELECTION...............................................................286.4. CURRENT TRANSFORMERS INSTALLATION ....................................................................................30

6.4.1. CT’s connection to the PQFT......................................................................................306.4.2. CT’s connection topology: cases ................................................................................31

6.4.2.1. Case 1: Global compensation – one feeding transformer................................326.4.2.2. Case 2: Individual compensation – one feeding transformer ...........................336.4.2.3. Case 3: global compensation – transformer busbar not accessible. ................336.4.2.4. Case 4: two independent feeding transformers..............................................356.4.2.5. Case 5: back up generator ...........................................................................36

6.5. CONNECTION OF LAMPS AND BUTTONS (IP00 VERSION) .................................................................376.6. PRECAUTIONS WITH CAPACITORS ...............................................................................................37

7. MASTER-SLAVE INTERCONNECTIONS ........................................................................................38

7.1. INTRODUCTION........................................................................................................................387.2. MECHANICAL INSTALLATION (CUBICLE VERSION) ...........................................................................387.3. ELECTRICAL CONNECTIONS .......................................................................................................39

7.3.1. Connections between sections ...................................................................................397.3.1.1. Power connection........................................................................................397.3.1.2. Control connection.......................................................................................407.3.1.3. Domino boards connection...........................................................................407.3.1.4. Earth connection .........................................................................................41

7.3.2. Connections to the supply..........................................................................................417.3.2.1. Power connection........................................................................................417.3.2.2. Protective earth...........................................................................................41


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8. PQF-PROG INSTALLATION AND PC CONNECTION......................................................................42

8.1. SYSTEM REQUIREMENTS...........................................................................................................428.2. INSTALLING PQF-PROG ON YOUR PC.........................................................................................428.3. HARDWARE CONNECTION..........................................................................................................42

9. COMMISSIONING ..........................................................................................................................43

9.1. STEP 1 ..................................................................................................................................439.2. STEP 2 ..................................................................................................................................439.3. STEP 3 ..................................................................................................................................43

9.3.1. PQF connection diagram............................................................................................449.3.2. Material needed & hypotheses for correct measurements ............................................449.3.3. Checking the correct connection of the CTs with a two channel scopemeter. .................44

9.3.3.1. Measurement of CT in phase L1...................................................................449.3.3.2. Measurement of CT in phase L2 and L3........................................................46

9.3.4. Checking the correct connection of the CTs with two current probes. ............................479.3.5. Checking the correct connection of the CTs with a Fluke 41B.......................................48

9.4. STEP 4 ..................................................................................................................................489.4.1. With PQF-Prog ..........................................................................................................489.4.2. With the PQF-Manager ..............................................................................................49

9.5. STEP 5 ..................................................................................................................................499.6. STEP 6 ..................................................................................................................................509.7. STEP 7 ..................................................................................................................................509.8. STEP 8 ..................................................................................................................................50

10. OPERATION ..................................................................................................................................51

10.1. NORMAL WORKING SEQUENCE....................................................................................................5110.2. ADDITIONAL INSTALLATION INSTRUCTIONS FOR THE PQFT IN THE PRESENCE OF PLAIN CAPACITORS ......5510.3. BEHAVIOR IN CASE OF POWER OUTAGE........................................................................................5510.4. BUTTONS, LIGHTS AND LED’S SIGNIFICATION................................................................................56

10.4.1. Master cubicle. ..........................................................................................................5610.4.2. Slave cubicle.............................................................................................................5610.4.3. PQF-Manager ...........................................................................................................5710.4.4. Control rack. .............................................................................................................57

10.5. PROGRAMMING WITH PQF-PROG ...............................................................................................5810.5.1. Filter operation principle. ............................................................................................5810.5.2. Starting .....................................................................................................................5910.5.3. Programming the filter................................................................................................61

10.6. PROGRAMMING WITH PQF-MANAGER .........................................................................................6210.6.1. Filter operation principle. ............................................................................................6210.6.2. Keys identification......................................................................................................6310.6.3. Programming the filter. ...............................................................................................64

10.7. PQFT AND NETWORK MONITORING WITH THE PQF-MANAGER.........................................................6710.7.1. Filter status. ..............................................................................................................6710.7.2. Network status ..........................................................................................................6810.7.3. Waveform .................................................................................................................6910.7.4. Spectrum ..................................................................................................................70

10.8. REMOTE CONTROL AND ALARM CONTACT .....................................................................................7110.8.1. Remote control ..........................................................................................................7110.8.2. Alarm contact ............................................................................................................71

10.9. PROTECTIONS .........................................................................................................................71

11. FAULT HANDLING AND TROUBLESHOOTING .............................................................................72

11.1. FAULT HANDLING .....................................................................................................................7211.1.1. Type of faults ............................................................................................................7211.1.2. Fault handling and fault clearance procedure...............................................................72

11.2. TROUBLESHOOTING..................................................................................................................7511.2.1. Frequent problems occurring at commissioning stage..................................................7511.2.2. Error codes meaning..................................................................................................7511.2.3. Faults not related to error codes .................................................................................7711.2.4. Restarting the filter after fault correction......................................................................78


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12. MAINTENANCE.............................................................................................................................79

12.1. MAINTENANCE FREQUENCY .......................................................................................................7912.2. MAINTENANCE PROCEDURE.......................................................................................................7912.3. FAN.......................................................................................................................................7912.4. CAPACITORS REFORMING ..........................................................................................................80


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1. Safety instructions

These safety instructions are intended for all work on the PQFT.Neglecting these instructions can cause physical injury and death.

All electrical installation and maintenance work on the PQFT should be carried out by qualifiedelectricians.

Do not attempt to work on a powered PQFT.

After switching off the mains, always wait at least 15 minutes before working on the unit in order toallow the discharge of DC capacitors through the discharge resistors.DC capacitors might be charged to more than 800V.

Before manipulating current transformers, make sure that the secondary is short-circuited. Neveropen the secondary of a loaded current transformer.

You must always wear isolating gloves and eye-protection when working on electrical installation.Also make sure that all local safety regulations are fulfilled.

WARNING: This filter contains capacitors that are connected between phase and earth ; a leakagecurrent will flow during normal operation, therefore a good earth connection isessential and must be connected before applying power to the filter.

WARNING: If the ground is defeated, certain fault conditions in the unit or in the system to which itis connected can result in full line voltage between chassis and earth ground. Severeinjury or death can then result if the chassis and earth ground are touchedsimultaneously.

WARNING: The neutral current in PQFT filter may be as high as 3 times the line current henceplease do not use a 4 pole breaker to connect this type of filter as the rating of theneutral pole may not be adequate.


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2. Upon reception

2.1. Delivery inspection

Each PQFT is delivered in a sealed package designed to protect adequately the equipment during shipment.Upon receipt of the equipment, make sure that the packing is in good condition.

After removal of the packing, check visually the exterior and interior of your filter. Any loss or damage shouldbe notified immediately.Care should be taken to ensure that correct handling facilities are used.

2.2. Identification tag

Each PQFT is fitted with a nameplate for identification purposes. The nameplate includes the type of filter,nominal frequency, voltage and current as well as a serial number and an ABB internal article code.This information should always remain readable to ensure proper identification during the whole life of thefilter.

2.3. Storage

PQFT packing is made for an indoor storage period of maximum six months (transport time included fromdelivery date EXW ABB Jumet factory). Packing for longer storage period can be done on request.If your PQFT is not installed once unpacked, it should be stored in a clean indoor, dry dust free and non-corrosive environment. The storage temperature must be between –15°C and 70°C with a maximum relativehumidity of 95%, non-condensing.

Before installing and operating your PQFT, you should read very carefully this instructions manual and youshould make sure that the information given on the nameplate corresponds to your network.

2.4. Long storage period and reforming

If your PQFT is non-operational or stored for more than one year, the DC capacitors need to be reformed (re-aged). Without reforming, capacitors may be damaged when the filter starts to operate.The reforming methods are described in chapter 12 (maintenance).


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3. PQFT principle and characteristics

3.1. Reasons for limiting harmonics

Power electronics based equipment is the main source of the harmonic pollution in electric networks.Examples of such equipment include drives (AC or DC), UPS’s, welders, PCs, printers etc.In general, the semiconductor switches in this equipment conduct only during a fraction of the fundamentalperiod. This is how such equipment can obtain their main properties regarding energy saving, dynamicperformance and flexibility of control. However, as a result a discontinuous current containing a considerableamount of distortion is drawn from the supply.

Harmonic pollution causes a number of problems. A first effect is the increase of the RMS-value and thepeak-value of the distorted waveform. This is illustrated in figure 3.1. that shows the increase of thesevalues as more harmonic components are added to an initially undistorted waveform. The RMS-value andthe peak-value of the undistorted waveform are defined as 100 %. The peaks of the fundamentalcomponent and the distortion components are assumed to be aligned. It may be seen that the distortedwaveform, which contains harmonics up to the 25th harmonic, has a peak value that is twice the value of theundistorted waveform and a RMS-value that is 10 % higher.

Peak: 100 % 133 % 168 % 204 %RMS: 100 % 105 % 108 % 110 %

Figure 3.1. Evolution of the increase in peak-value and the RMS-value of a waveform as moreharmonic components are added

The increase in RMS-value leads to increased heating of the electrical equipment. Furthermore, circuitbreakers may trip due to higher thermal or instantaneous levels. Also, fuses may blow and capacitors maybe damaged. kWh meters may give faulty readings. The winding and iron losses of motors increase andthey may experience perturbing torques on the shaft. Sensitive electronic equipment may be damaged.Equipment, which uses the supply voltage as a reference may not be able to synchronise properly and eitherapplies wrong firing, pulses to switching elements or switch off. Interference with electronic communicationsequipment may occur.Distorted networks may also cause generators malfunctions.Homopolar harmonics (third and multiple of three) generated by loads connected between phases and/orloads connected between phase and neutral are strictly in phase. When the neutral is connected, thehomopolar currents are added in the neutral line.

100 % H1 + 33 % H3 + 20 % H5 … + 4 % H25


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Fundamental

3th

Fundamental

3th

Fundamental

3th

3th

N

L3

L2

L1


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This situation becomes critical when the neutral conductor section is only a fraction of the line conductor.This excessive neutral conductor temperature is witnessed sometimes leading to neutral conductordestruction.Overall it may be concluded that an excessive amount of harmonics leads to a premature ageing of theelectrical installation. This is an important motivation for taking action against harmonics.

3.2. General principle of active filtering

The active filter measures the harmonic currents and generates actively a harmonic current spectrum inopposite phase to the measured distorting harmonic current. The original harmonics are thereby cancelled.The principle is shown in figure 3.2.

Figure 3.2. Principle of active filtering

The control of the active filter in combination with the active generation of the compensating current allowsfor a concept that may not be overloaded. Harmonic currents exceeding the capacity of the active filter willremain on the network, but the filter will operate and eliminate all harmonic currents up to its capacity.

The principle of active filter showing currents and spectra is clarified in Figure 3.3.

PQFT

Supply Load

Fundamental only

- 1.3

1 .3

0 3 6 0

-1.3

1.3

0 360

-1 . 3

1.3

0 360

idistortion

icompensation


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Figure 3.3. Active filter principle illustrated in time and frequency domains

3.3. The ABB Active filter: the PQFT.

As we have just seen, the active filter is basically a compensating current generator. The most importantparts are then the current generator and the control system.

The compensating current is in a first step created by a three-phase Insulated Gate Bipolar Transistors(IGBT) inverter bridge that is able to generate any given voltage waveform with PWM (Pulse WidthModulation) technology. The IGBT bridge uses a DC voltage source realised in the form of a DC capacitor.The inverter bridge is in fact the same technology than in AC drives.The generated voltage is coupled to the network via reactors and a small filter circuit. The desired currentgenerator is thereby achieved.

The DC capacitors are loaded actively through the inverter bridge and there is no need of external powersource. Obviously, the DC voltage level must always be higher than the peak value of the network voltage inorder to be able to inject currents to the network.To control the active filter the choice stands between open loop and closed loop current control. Under openloop current control, the harmonics currents are measured on the load side of the active filter that computesthe required compensating current and injects it into the network.

Closed loop current control as performed by the PQFT is shown in Figure 3.4. In this topology the resultingcurrent to the network is measured and the active filter operates by injecting a compensating currentminimising this resulting current. In this configuration, the filter directly controls its effect on the filtration.

+= Load current

1 5 7 11 13 17 19

-20

0

20

40

1 5 7 11 13 17 19

Active Filtercurrent

1 5 7 11 13 17 19

-20

0

20

40

1 5 7 11 13 17 19

Cleanfeedercurrent

1 5 7 11 13 17 19

-20

0

20

40

1 5 7 11 13 17 19

Wav

efo

rms

Har

mo

nic

s-1.3

1.3

0 360

- 1 . 3

1.3

0 360

- 1 . 3

1.3

0 360


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Figure 3.4. Closed loop control

In addition to being more precise, the closed loop control system also allows for a direct control of the degreeof filtering. Furthermore, the closed loop control system ensures that measurement errors do not result in ahigher distortion.

To fully exploit the potential of an active filter we need a digital measurement and control system that is fastenough to operate in true real time. We need to be able to track the individual harmonics and control thecompensating current according to the requirements of the plant and this with full control at every instant intime. To achieve this, we need advanced Digital Signal Processors, DSP’s.

Among the physical signals needed by the PQFT, the three line currents have obviously to be measured.Standard CTs with 5A secondary are usually sufficient. Those analogue signals must first be acquired,levelled and antialias-filtered before digitalisation. Fast and high precision analogue-to-digital converters areused to create a digital representation of the analogue signals. The digitised signals are then sent to thepowerful DSP that controls all measurements and calculations in real time, and builds the PWM referencesfor the inverter. It is another processor, a microcontroller, which handles all digital input/output (including thecommand of the PWM inverter). More dedicated to control than to calculations, this microcontroller ensuresfor instance the closing of the relays and contactors.One control is needed per PQFT system and can handle more than one power module simultaneously.

Control

AF

Target

Measurement Feedback

Output


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3.4. The PQFT: performances

3.4.1. Filtering

The main requirement for an active filter installed in an industrial installation is to attenuate the harmonicsproduced by the non-linear loads of the installation.The ideal active filter should allow the user to choose freely which harmonic components to filter and shouldoffer an adjustable degree of filtering.It is also worth noting that the total harmonic voltage distortion at the point of common coupling (PCC) isoften calculated up to the 40th [1] or the 50th [2] harmonic. Furthermore, the total number of harmonics thatcan be filtered determines directly the quality of the resulting current. This is illustrated in figure 3.5., whichshows the filtered waveforms obtained by filtering up to different harmonic levels.

(a) Filtering up to the 13th harmonic.

(b) Filtering up to the 25th harmonic.

(c) Filtering up to the 50th harmonic.

Figure 3.5. Waveforms obtained by eliminating the harmonic components of a rectangularperiodic signal up to the (a) 13th harmonic, (b) the 25th harmonic and (c) the 50th harmonic

This figure highlights the need for an active filter that can operate up to sufficiently high harmonicfrequencies.

The PQFT can filter simultaneously 15 (12) independent harmonics up to the 50th for 50Hz (60Hz) basednetworks. The number of harmonics to be filtered as well as their frequencies is completely programmable bythe user.

Besides the harmonic selection functionality, the user has also the possibility to specify a filtration level foreach selected harmonic. The PQFT will filter the selected harmonics until the filtration level set by the user isreached. This filtration level can be different for each selected harmonic. This functionality is especiallyuseful when the objective is to fulfil the requirements of a standard and results in a better use of the availablecompensation power. It also allows the installation of active filters on networks already fitted with a fixedpassive filter.

We can see that we are very close to the ideal filter: the choice of which harmonic components to filter is freeand the degree of filtering is adjustable according to the wishes of the user.Moreover, all typical harmonics generated by non-linear loads may be filtered simultaneously.


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3.4.2. Reactive power

Besides the filtering functionality, reactive power compensation is also possible with the active filter.Compared to traditional capacitor banks, the reactive compensation of the PQFT is continuous (‘stepless’),fast and smooth (no transients at switching). The compensation can be either capacitive or inductive.Two types of compensation are available: automatic compensation where a target power factor has to beset, and fixed compensation based on a predefined amount of kvar.

3.4.3. EMC

The PQFT has been verified for compliance with EU (European Union) directives for EMC (electromagneticcompatibility) for operation at 50 Hz and bears the CE-mark to this effect. However it is assumed that theinstallation is done as per the instructions in this manual.When an apparatus is used in a system, EU directives may require that the system is verified for EMCcompliance. For EMC reasons, the cubicle should be connected to the main protective earth connection withyellow-green wire. This wire should be as short as possible.


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4. Components description and identification

4.1. Components description

As already explained, the active filter is basically composed of two parts: the current generator and thecontrol system.

4.1.1. PQF current generator.

The power circuit of the ABB active filter PQF is represented hereafter.

OutputFilter

PWM inverter

Main Breaker

PowerLines

+

-

PWM Reactors

Preload

The main components are:- PWM inverter- PWM reactors- Output filter- Preloading circuit

The current generator is physically organised in power modules, each including a PWM inverter, a three-phase PWM reactor and the output filter.Each PQFT plate or cubicle contains one power module. Protection is realized through fuses and there isone preloading circuit.

The PWM inverter is composed of DC capacitors and an IGBT inverter bridge. This system is able togenerate any voltage waveform with PWM technology.

Non-linear load(s)- three-phase withor without neutralconnection- single-phase

PQF DigitalControl

Compensationcurrent

Currentmeasurement

PQF currentgenerator


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The physical layout of a PWM inverter module is shown hereafter.

Each PWM inverter is fitted with a local electronic control called the domino board. The domino board iscontrolled by the central DSP. The domino board is fitted with jumpers noted JP100, JP101, JP102, JP103,JP104, JP105, JP106, JP109 and JP110 (JP107 and JP108 are off). In case of several power modules, onlythe domino board of the last slave is fitted with jumpers. Please refer the photo below.

The PWM reactors convert the voltage created by the PWM inverter into currents that will be injected in thenetwork.

The output filter consists in line reactors and an RC shunt circuit.

The function of the preloading circuit is to avoid at start-up high inrush currents that could damage the powerelectronics or create transients in the network.


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4.1.2. The control

For best performances, the control of the PQFT is Digital Signal Processor (DSP) based.

The three lines currents are measured by external CT. Those analogue signals must first be acquired,levelled and antialias-filtered before digitalisation. Fast and high precision anlogue-to-digital converters areused to create a digital representation of the analogue signals. The digitised signals are then sent to thepowerful DSP that controls all measurements and calculation in real time, and builds the PWM references forthe inverter. It is another processor, a microcontroller, which handles all digital input/output (including thecommand of the PWM inverter). More dedicated to control than to calculations, this microcontroller ensuresfor instance the closing of relays and contactors.

One control unit may command up to 4 power modules.

4.2. Components identification

PQFManager

PWMinverter

Control

Auxiliaryvoltagetransformer

Mainfuses

Output filtercapacitor

Fan


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A more detailed identification is given in the following pages.

The identification hereafter is related to the drawings of the following pages. Internal views indicate theposition of identified components but fixation details are not included. Although visible on the drawings, somecomponents may actually be hidden in the real structure.

Mains connection

F102 mains fusesK10 mains contactor

Fan

M101 fan motor

Auxiliaries

Q101 breaker for auxiliariesT101 auxiliary voltage transformer

PWM inverter

U11 IGBT moduleA67 AC voltage boardA77 Domino interfaceA104 DC voltage converterA105 DC voltage converterA117 Domino board

Output filter

C11 Output filter capacitorL11 Line reactorL12 Line reactorL13 Line reactor

PWM reactor

L21 PWM reactorL22 PWM reactorL23 PWM reactor

Preloading circuit

K11 Preload contactorR14/15 Preload resistorsU1 Preload bridge


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Control rack

A111 Digital I/O boardA112 Interface board – IGBT’s and DSPA113 Digital Signal Processor (DSP Board)A119 Interface PQF Manager boardA114 Current input boardA115 Analog input boardA116 +24V power supply boardU109 Power supply + 5VX1 Terminal block digital I/O wiringX4 Terminal block current input wiringX2 Terminal block analog input wiringX10 Terminal power supply wiringX6 Terminal current input wiring

Door components

S102 RESET push buttonS101 RUN push buttonS104 Remote local switchH101 White lamp: controller connected to supply (auxiliary breaker closed)H102 Red lamp: MCB closedH103 Green lamp: MCB openA120 PQF-Manager

Other components

A121 +24V switching power supply

X5 Terminal block backplane wiring (external CT connection)

X12 Terminal signalling wiring

X21 Terminal intercabinets wiring


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Master + slave IP00


20


21

Control rack details


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5. Mechanical installation

5.1. Generalities

The PQFT is suitable for indoor installation, on firm foundations, in a well-ventilated area without dust andexcessive aggressive gases where the ambient parameters do not exceed the following values:

40°C max (including the PQFT heat generation);(please refer to page 23)

30°C (average temperature) over 24 hours;

Minimum temperature: +5 °c

Humidity less than 95% RH non-condensing

Altitude: max. 1000m without derating.

For units with nominal voltage above 415V, the rear side of the cubicles must be located at least at 100mmfrom the wall.

PQFT cubicles (IP23 version) have standard dimensions of 600 x 600 x 2150 mm (width x depth x height).

PQFT plates (IP00 version) have standard dimensions of 499 x 400 x 1696 mm (width x depth x height).

Each cubicle or plate is fitted with one power module, its own bottom cable entry (top cable entry onrequest), fuses and contactor.

Standard arrangement for PQFT with up to 3 power modules are shown on page 23.A maximum of 4 power modules may be connected in parallel.

!!!!!!!!!!!!!!!! Only modules of the same ratings may be paralleled !!!!!!!!!!!!!!!!!!!!!!!

CAUTION

The PQFT dissipates significant amounts of heat; 3 kW/module that has to be evacuated out of the roomwhere the filter is located. Otherwise, you may experience excessive temperature rise. Please note life ofelectrical equipment decreases drastically if the operating temperature exceeds the allowable limit.


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For proper cooling of the PQFT, a minimum airflow of 610 m3/h of cooling air has to be supplied to the eachfan of the unit. Please ensure the air used for cooling does not contain conductive particles, significantamounts of dust, or corrosive or otherwise harmful gases.The cooling air intake temperature cannot exceed 40°C under any operating condition. The fan inlet must notbe covered by any object and located at a sufficient distance from walls to ensure a correct air flow.The hot exhaust air has also to be properly ducted away.


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5.2. IP00 plate

5.2.1. Mounting of the plate

The IP00 mounting plate is to be fixed in your own cubicle by means of the four holes located in the cornersof the plate. Please refer to the attached diagram.Six holes are provided to fix the plate in the cubicle with M8 screws. The holes at halfway up are used toclamp the plate in the cubicle and to increase its rigidity while the other ones are mainly for the principalfixations.

For proper cooling of the PQFT, a minimum airflow of 610 m3/h of cooling air has to be supplied to each fanof the unit. It must be fed with fresh air through the bottom of the door and it must be free to go out from thetop of the cubicle.Please ensure the air used for cooling does not contain conductive particles, significant amounts of dust, orcorrosive or otherwise harmful gases.


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5.2.2. Master cubicle door accessories

The dimensions of the cut-out to be made on the master cubicle door are represented here below.There are 6 holes for buttons and lamps (same dimensions) and the cut-out for the PQF-Manager (ifdelivered). The buttons and lamps are provided with the filter.The positions of the cutout are those of the IP23 version and are given for indication only.Also please follow the following steps to fit the metallic cover on PQF-Manager as follows:- unscrew the RS232 spacer screws on the PQF-Manager itself- place the manager on one side of the door and the metallic cover on the other side- hold the cover with the spacer screws- fix mechanically the whole assembly to the door

5.2.3. Slave cubicle door

Only one lamp is provided to be installed on slave cubicle doors. The dimension of the cutout is the samethan for the master cubicle door (diameter: 23 mm).


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6. Electrical installation

Your PQFT is a parallel active filter: it is installed in parallel with the load(s).

Connection implies:- 3 power cables- 1 neutral cable- 3 CT (one per phase)- 6 control wires for the CT- Ground/PE

6.1. Overvoltage

The PQFT is able to withstand continuously a voltage (inclusive of harmonics but not transients) of up to110 % of the rated voltage. Higher voltages than the rated one would imply an operation at limited power ofthe filter. Since operation at the upper limits of voltage and temperature may reduce its life expectancy, thePQFT should not be connected to systems for which it is known that the overvoltage will be sustainedindefinitely.

6.2. Power cables and external protection

Each cubicle is fitted with its own fuses (bottom cable entry (top cable entry on request)) and needs to beindividually connected to the supply.

The power cable size should be rated on the basis of X times the nominal current of the correspondingcubicle (one or two power modules) where X is a multiplication factor which allows to take into account theskin effect.

This multiplication factor is the result of an iterative calculation and can be determined by means of thefollowing process:

Important remark: please note that the following process is made to take into account the skin effect only.Other deratings due to local standards and/or installation conditions (as e.g. cables proximity, number ofcables connected in parallel,…) have to be taken into account by the company responsible for the PQF cableconnection.

Step 1: as initial value of this iterative process, determine the preliminary cable section on the basis of thenominal current.

Step 2: based on the previously determined cable section, find in the table here below the multiplicationfactor that must be applied.

Step 3: determine the cable section on the basis of the value of the multiplication factor times the nominalcurrent.

- if the cable section found is equal to the previously found cable section, the process can be stopped.The cable section is then determined taking into account the skin effect.(see examples below)- If the cable section found is bigger than the previously found value, step 2 and 3 have to be repeateduntil the cable sections are equal (see example below).


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SSeeccttiioonn 50Hz 60Hz[mm2] Al Cu Al Cu

16 1.01 1.01 1.01 1.0125 1.01 1.02 1.01 1.0335 1.02 1.03 1.02 1.0450 1.03 1.06 1.04 1.0870 1.05 1.1 1.06 1.1395 1.08 1.16 1.10 1.21120 1.11 1.30 1.15 1.30150 1.16 1.30 1.21 1.39185 1.22 1.41 1.28 1.50240 1.31 1.55 1.40 1.66300 1.41 1.70 1.52 1.84

Table: Multiplication factors for different cable types

Example:Please note that the following example is given for information only(see important remark above).

PQF-T 70A 400V 50hz

Phase cables sizing

Step 1: IN = 70A à cable section (*) = 25 [mm2]

Step 2: multiplication factor for a 25 [mm2] copper cable at 50hz = 1.02

Step 3: I = IN x 1.02 = 70A x 1.02 = 71.4 A

Step 4: I = 71.4 A à cable section (*) : 25 [mm2]

This section is equal to the section found in the previous step.

Result : one copper cable of 25 [mm2] per phase

(*) given for information only.

Neutral cable sizing

Step 1: IN = 210A à cable section (*) = 120 [mm2]

Step 2: multiplication factor for a 120 [mm2] copper cable at 50hz = 1.1

Step 3: I = IN x 1.1 = 210A x 1.1 = 231 A

Step 4: I = 231 A à cable section (*) : 120 [mm2]

This section is equal to the section found in the previous step.

Result : one copper cable of 120 [mm2] for neutral cable connection.

(*) given for information only.

If single core cables are used an alloy gland plate is recommended.The neutral current in PQFT filter may be as high as 3 times the line current hence please do not use a 4pole breaker to connect this type of filter as the rating of the neutral pole may not be adequate.PQF-T copper bar dimensions for connection of phases and neutral cables:30 mm x 10 mm (hole: ∅ = 11 mm)


28

NOTE: Due to the LCL output filter of the PQF, there is no radiated emission through the feeding cables.Consequently, there is no need for special screening of the incoming cables.

In case of regenerative loads (e.g. loads that may inject active energy to the network, usually called 4Q-loads), it is very important to connect the PQF outside the protection of this load.Indeed, consider Figure 6.1 where a common protection is installed for both the regenerative load and for thePQF. When the load reinjects energy to the network and the mains protection trips, the whole energy may bepushed into the PQF, which may cause severe inquires to it.Figure 6.2 shows the admitted protection scheme for regenerative loads. In this case, if the breaker of theload trips, the PQF is isolated from the fed back energy.

PQF4Qload

Figure 6.1. Incorrect connection

6.3. Current transformers/control cables selection

Three CT’s are needed since the PQFT monitors the three phases and neutral of the network.

The proper operation of the PQFT does not require any special CT’s. The requirements are minimum:

• 5A of secondary• 15 VA minimum for up to 30 meters of 2.5 mm² cable• Class 1 accuracy or better• Ratio limit above maximum line current

In case the CT’s are shared with other loads, the VA burden shall be adapted and the connection of thedifferent loads (including the PQFT) must be in series.

Twin 2.5 mm² control cable is the most suitable for this application.

In order to determine the suitable CT’s for your application, please refer to the following chart.

PQF4Qload

Figure 6.2. Correct connection


29

Max

imum

rm

s cu

rren

t of t

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wns

tream

load

s (in

clud

ing

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ting

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ent o

f DC

driv

es):

X1

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.. A

rms

Mul

tiply

X1

by1.

6:

X2

= …

. Arm

s

CT

cab

les

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met

ers

?

Sel

ect 3

iden

tical

CT

’s s

uch

that

:- r

atin

g a

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ary

≥ X

2- r

atin

g a

t sec

on

dar

y: 5

A- B

urd

en ≥

15

VA

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lass

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ccu

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or

bet

ter

NO

Sec

tion

of C

T ca

bles

:

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mm

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eter

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L =

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X3

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x 0

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5) +

10

X3

= …

VA

Sel

ect 3

iden

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CT

’s s

uch

that

:- r

atin

g a

t p

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5A- B

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ss 1

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th (

m)

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ce (Ω

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able

s (m

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R =

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x R

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5) +

10

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= …

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CT

’s s

uch

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:- r

atin

g a

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5A

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en ≥

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bet

ter

NO

YE

S

YE

S


30

6.4. Current transformers installation

Special care has to be taken for the connection and location of the CT’s: it is the most current source ofproblems occurring at commissioning stage.

WARNING: when connecting the CT’s to the PQFT, the secondaries of the CT’s have to be short-circuited.

First of all, the CT’s have to be positioned for closed loop control: they have to monitor the resulting currentafter filtering.

The CT’s must also be positioned in the correct direction around the power cable: the K (or P1) side shouldbe in the direction of the supply and the L (or P2) side should be in the direction of the load.

6.4.1. CT’s connection to the PQFT

The connections between the CT’s and the filter must satisfy the following scheme:

• The k terminal of line 1 CT is connected to terminal X5-1 of the filter• The l terminal of line 1 CT is connected to terminal X5-2 of the filter



L1

L2L3

Loadside

Supplyside

K L

k l

K L

k l

K L

k l

PQF

X5.2X5.3X5.4X5.5X5.6

X5.1

L1 L2 L3 N

N


31

6.4.2. CT’s connection topology: cases

The location of the CT’s is critical to ensure the proper operation of the active filter. The CT’s are the “eyes”of the filter and it will react in accordance with the information supplied by them.

The location of the CT’s must always be in closed loop configuration. This means that the CT’s must see theload current and the filter current.In some cases, summation CT’s might be needed to fulfil the closed loop requirement.

Typical circuit topologies and adequate CT’s location are described hereafter in the following order:

Case 1: Global compensation – one feeding transformer.Case 2: Individual compensation – one feeding transformer.Case 3: Global compensation – transformer busbar not accessible.Case 4: Two independent feeding transformers.Case 5: Back up generator.

Please bear in mind that the active filter always needs 3 CT’s: one per phase.There is also one shorting bridge per CT input on terminal X5. Those bridges must be removed only whenthe secondary circuit of the CT is closed.


32

66..44..22..11.. CCaassee 11:: GGlloobbaa ll ccoommppeennssaa ttiioonn –– oonnee ffeeeeddiinngg ttrraannssffoo rrmmeerr

This is the most frequent configuration: one transformer feeds several non-linear loads. The active filter isinstalled in central position and filters the combined harmonic currents.

This configuration and the proper location of the CT’s is represented hereafter.

Figure 6.3. Global compensation – one feeding transformer.

The connection of the CT’s to the active filter must be as represented herafter:

L1

L2L3

Loadside

Supplyside

K L

k l

K L

k l

K L

k l

PQF

X5.2X5.3X5.4X5.5X5.6

X5.1

L1 L2 L3 N

N

Figure 6.4. CT’s connection to the active filter.

PQF LOAD LOAD LOAD

K = P1, L = P2, k = S1, l = S2


33

66..44..22..22.. CCaassee 22:: IInnddiivviidduuaa ll ccoommppeenn ssaa ttiioonn –– oonnee ffeeeeddiinngg ttrraannssffoorrmmeerr

Instead of installing one active filter in central position, it also possible to connect the active filter and its CT’sso that it compensates one particular load only.In the example hereafter, the active filter PQF is connected to compensate Load 1 only. It does not see load2.

Figure 6.5. Individual compensation – one feeding transformer

The connection of the 3 CT’s to the active filter is described in 6.4.1.

66..44..22..33.. CCaassee 33:: gglloobbaa ll ccoommppeenn ssaa ttiioonn –– ttrraann ssffoorrmmeerr bbuu ssbbaarr nnoott aaccccee ssssiibbllee ..

The active filter is required to filter the loads of side A and side B but the transformer busbar not beingaccessible, the CT’s cannot be installed in central position.

Figure 6.6. Transformer busbar with no access: single-line diagram

For this configuration, three CT’s (one per phase) have to be installed on side A et on side B (in total, 6CT’s). Those CT’s will then feed 3 summation CT’s (one per phase) that are connected to the active filter.This CT topology is represented in figure 6.7.

LOAD 2

LOAD 1PQF

LOADS(Side A)

LOADS(Side B) PQF


34

Figure 6.7. Transformer busbar with no access: CT connection (to be done for each phase)

The CT’s installed in each phase of side A et B (CT1 and CT2) must be identical (X / 5) and feed asummation CT whose secondary is 5A (5+5/5A). The summation CT is then connected to the active filter inaccordance with chapter 6.4.1.

A total of 3 summation CT’s (one per phase) must be used. The CT ratio to be programmed in the filter is: 2X/ 5.

The CT – summator – PQF connection is represented here below. This has to be done for each phase.

Figure 6.8. Connection between CT1, CT2 , the summation CT and PQF for one phase.

LOADS(Side A) LOADS

(Side B)

PQF

Summation CT(one per phase)Primary 1: 5 APrimary 2: 5ASecondary: 5A

CT 1 (one perphase)Primary: XSecondary: 5A CT 2 (one per

phase)Primary: XSecondary: 5A

S1, k

S2, l

S1, k

S2, l

P1

P2

P1

P2

S1

S2

k

l

PQF

Side A Side B

P1, K

P2, L

P1, K

P2, L


35

66..44..22..44.. CCaassee 44:: ttww oo iinnddeeppeennddeenntt ffeeeeddiinngg ttrraannssffoorrmmeerr ss..

Two independent transformers (the tie is normally open) feeds two different set of loads. One active filter isfitted on each LV busbar.This system may however also work in degraded mode: the tie is closed and only one transformer feeds thewhole LV system.By connecting the CT’s as described hereafter, it is still possible to filter properly the harmonics and tocorrect the power factor.

Figure 6.9. Two independent transformers: single-line diagram

Figure 6.10. Two independent transformers: CT connection for one phase.

PQFPQF

T1 T2

S1, k

S2, l

P1 P2 P1 P2

S1 S2

S1, k

S2, l

S1k

S2l

P1 P2 P1 P2

S1 S2

I1 I2I0

I’1-I’0

PQF 1

I’2+I’0

PQF 2

k l k l

T1 T2

P2, L

P1, K P1, K

P2, LP1K

P2L


36

For each phase, 3 CT’s must be installed: - one to measure I1- one to measure I2- one to measure I0.

Those CT’s must be identical: X/5 A.CT I1 and CT I0 feed a summation CT which is connected to PQF1.CT I2 and CT I0 feed a summation CT which is connected to PQF2.

Those summation CT’s must be 5+5 / 5 A.

Condition 1: the tie is open.

PQF1 sees I1 and PQF2 sees I2 (I0 = 0). The two transformers work independently and the total current tobe compensated is I1 + I2.

Condition 2: the tie is closed but both transformers feed the loads.

In this configuration, PQF1 sees (I1-I0) and PQF2 sees (I2+I0). The total current seen by the two filters is I1+ I2.

Condition 3: the tie is closed but only one transformer feeds the loads (degraded mode).

If only T1 feeds the loads with the tie closed, PQF1 sees (I1-I0) and PQF2 sees I0 (I2 is zero). If only T2feeds the load, I1 will be zero.The above described connection must be done for each phase. The CT ratio to be programmed in the filteris: 2X/5.

66..44..22..55.. CCaassee 55:: bbaacckk uupp ggeenneerraa ttoorr

Many installations are fitted with back up generators to ensure the proper operation of the installation in caseof mains power outage.

A typical configuration is given here below.

Figure 6.11. Back-up generator: typical single-line diagram

G

LOAD PQF


37

The CT connection must be such that the active filter works whatever the type of supply: generators ortransformer-MV network.

For each phase, one CT is installed in the transformer feeding and one in the generator. Those two CT’smust be identical (X / 5 A) and are connected to a summation CT rated 5+5 / 5 A.The CT ratio to be programmed in the filter is: 2X/5.

Figure 6.12. Back-up generator: CT connection (for one phase)

6.5. Connection of lamps and buttons (IP00 version)

The buttons and lamps have to be connected to terminal X20 according to the following table for the mastercubicle:

Item Connection pointsGreen lamp (H103) X20-4 / X20-3Red lamp (H102) X20-5 / X20-3White lamp (H101) X20-6 / X20-3Local-remote switch (S104) X20-7 / X20-8 (local) / X20-9 (remote)Run button (S101) X20-8 / X20-10Reset button (S102) X20-8 / X20-11

The auxiliary power on lamp for the slave cubicle has to be connected to terminal X20 according to thefollowing table:

Item Connection pointsWhite lamp (H101) X20-1 / X20-2

6.6. Precautions with capacitors

Care must be taken while connecting the PQFL in parallel with a plain capacitor bank. For detailed, pleaserefer to chapter 10 (§ 2).

S1, k

S2, l

S1, k

S2, l

P1

P2

P1

P2

S1

S2

k

L

PQF

G

P1, K

P2, LP1, K

P2, L


38

7. Master-slave interconnections

7.1. Introduction

This section explains how to connect PQF sections (Master-Slave or Slave-Slave) when they do not comeconnected from the factory or in case of on-site extension.

The section starts with mechanical installation.

Electrical connections are then described: interconnections between sections and with the supply.

All cables needed to make the connections are supplied with the units.

A maximum of 4 power modules may be connected in parallel.

!!!!!!!!!!!!!!!! Only modules of the same ratings may be paralleled !!!!!!!!!!!!!!!!!!!!!!!

7.2. Mechanical installation (cubicle version)

The side panels of the cubicles to be interconnected have first to be removed (except the outside one of theMaster and last Slave cubicles).

The provided divider panel seal has to be fixed on the interior frame between cubicles.Cubicles are then interconnected at 6 fixation points as indicated in Figure 3.1.The baying kit is provided with the cubicles (not the tools).

Figure 7.1. Mechanical installation


39

7.3. Electrical connections

7.3.1. Connections between sections

77..33..11..11.. PPooww eerr ccoonnnneeccttiioonn

The DC bus of the master and slave sections must be connected.Each slave section comes from the factory with two cables connected on the + and - poles of the DC bus.

Those cables are then fixed to the terminals of the DC bus of the next section. The cables must run awayfrom the earth connection as far as possible.

Start the DC buses interconnection with the last slave and proceed similarly with each section until reachingthe Master.

An example of DC bus interconnection is given below (PQFT-master + 2 slaves) in Figure 7.2.

Figure 7.2. DC bus interconnection

Be very careful about the polaritywhen connecting the DC bus.(Please refer to the enclosed photo.)

Master

Control

+-

Slave 1+-

+-

+-

Internal

Externalconnection toperform

Slave 2+-

+-


40

77..33..11..22.. CCoonntt rrooll ccoonnnneeccttiioonn

• The following terminals of the master unit and the first slave unit must be interconnected (threeinterconnections):

Master Slave 1A X21-1 connected to X21-8B X21-2 connected to X20-2C X21-3 connected to X21-7D X21-4 connected to X21-6

• The following terminals of the first slave unit and the second slave unit must be interconnected (threeinterconnections):

Slave 1 Slave 2A X21-1 connected to X21-8B X21-2 connected to X20-2C X21-3 connected to X21-7D X21-4 connected to X21-6

• The following terminals of the second slave unit and the third slave unit must be interconnected (threeinterconnections):


• The following terminals of the second slave unit and the third slave unit must be interconnected (threeinterconnections):


77..33..11..33.. DDoommiinnoo bbooaarrdd ss ccoonnnneecc ttiioonn

The inter-domino boards connection is achieved with flat cables. The flat cable must run as close as possibleto the inside wall of the cubicle, close to the earthed part, away from the components.

Each slave section is fitted with a loose flat cable. The other end of this flat cable has to be connected to thefirst plug of domino board A118 of the next cubicle, starting at the last slave.Make sure that the plug-in pattern of the connector and plug is respected.

The last domino of the chain must be fitted with termination jumpers on positions JP100, JP101, JP102,JP103, JP104, JP105, JP106, JP109 and JP110 (JP107 and JP108 are off).

An example of domino boards interconnection is given in Figure 7.3


41

77..33..11..44.. EEaarrtthh ccoo nnnneeccttiioonn

The earth cable of each slave cubicle has to be connected to the earth connection point of the mastercubicle. Make sure that the cables run along the floor, not over components.The earth connection between master and slave shall be done using at least 16 sq.mm wire. The main earthconnection (between the earth bar of each cubicle and the earth) shall be done in accordance with localelectrical regulation.

7.3.2. Connections to the supply

77..33..22..11.. PPooww eerr ccoonnnneeccttiioonn

Four power cables (L1, L2, L3 and N) have to be connected to each busbar (one in each cubicle). The threephases are protected by fuses in each cubicle.Make sure that L1, L2 and L3 in each cubicle are connected to the same phases.

77..33..22..22.. PPrrootteeccttiivvee eeaarrtthh

The protective earth point of each cubicle has to be connected to earth.

The connections to the supply are represented in Figure 7.3.

Figure 7.3. Flat cables connection and connections to power supply

Internal connection

External connection to perform

DominoA118

DominoA118

DominoA118

Control

IGB

T M

odul

eM

AS

TE

R

IGB

T M

odul

eS

LAV

E 1

IGB

T M

odul

eS

LAV

E 2

L2L1 L3 N PE L2L1 L3 N PE L2L1 L3 N PE


42

8. PQF-Prog installation and PC connection

The PQF-Prog, included in the standard PQFT package, allows for the complete programming of the filter. Itconsists of two Micro Floppy Disks delivered with the filter.

8.1. System requirements

Windows NT 4.0 Service Pack 3 minimum.

At least one free COM:port (RS232 - DB 9).

One standard RS232 cable (male-female non twisted)

8.2. Installing PQF-Prog on your PC

1. Insert disk 1 of PQF-Prog in drive A2. In the Start Menu, choose Run3. In the Command Line box enter

a:\setup4. Follow the instructions in the dialog boxes to:

• Specify the drive and directory (c:\ Program Files \ Pqf is the default)• Complete the installation

8.3. Hardware connection

A111 A112 A113 A119 A114 A115 A116 U109DIG INT DSP GUI LIC LVI ALIM/GND +5V

YELLOW LEDGREEN LED

RED LED

1 2

3

21

3

21 21 21 1

1 2

3

RS232-port

If your filter is equipped with the PQF-Manager, you just have to plug the DB 9 connection inthe RS232 port situated at the front of the PQF-Manager.

If your filter is not equipped with the PQF-Manager, you have to plug the connection in theRS232 port located on the control rack (A111: digital I/O board) as shown here after.


43

9. Commissioning

The commissioning of your PQFT should be conducted in strict accordance with the following procedure.

Warning: Before applying the commissioning procedure, make sure that you become familiar withprogramming instructions (see chapter 10, programming with PQF-Prog and PQF-Manager).Pay particular attention to the presence of capacitors on the network.

The commissioning procedure consists in 8 steps that should be followed very carefully.

Step 1 Installation checkStep 2 Voltage phase rotationStep 3 Current transformer checkStep 4 System set-upStep 5 Before starting the filterStep 6 Start the filterStep 7 Stop the filterStep 8 Start filtering

9.1. Step 1

Step 1: Visual and installation check

Check first that mechanical and electrical installations fulfil requirements described in chapter 4 and 5 of thepresent manual.

Check also visually the conditions of the filter and the tightness of connections. In particular, verify that allconnections on the control rack, domino board and IGBT are properly plugged in.

9.2. Step 2

Step 2: Voltage phase rotation

Voltage phase rotation must be clockwise (L1 -> L2 -> L3 -> L1). Wrong phase rotation may damage thefilter.

9.3. Step 3

Step 3: Current transformer check

Improper CT connection is the most frequent cause of problems during commissioning.

The following procedure will allow you to check the CT connection.

Warning: The secondary circuit of a loaded CT must never be opened otherwise extremely highvoltages may appear which can lead to physical danger or destruction of the CT itself.


44

9.3.1. PQF connection diagramFigure 9.1. shows the normal connection of the PQF. It must be noted that:• L1, L2 and L3 rotation must be clockwise,• The CTs must be on the supply (line) side of the PQF,• One secondary terminal of the CT must be earthed.

L1

L2L3

Loadside

Supplyside

K L

k l

K L

k l

K L

k l

PQF

X5.2X5.3X5.4X5.5X5.6

X5.1

L1 L2 L3 N

N

Figure 9.1. PQF connection

It is also seen that terminal X5.1 and X5.2 are related to the CT located in phase L1, terminal X5.3 and X5.4are related to the CT located in phase L2 and terminal X5.5 and X5.6 are related to the CT located in phaseL3.

9.3.2. Material needed & hypotheses for correct measurementsA two channel scopemeter with one voltage input and one current input is needed. Adequate sensors arealso needed. A power analyser like the Fluke 41B can also be used.Some minor knowledge of the load is also required. For instance, the method explained below is based onthe fact that the load is inductive and not regenerative (i.e. the load current lags by less than 90° the phasevoltage). If a capacitor bank is present, it is better to disconnect it before making measurements in order toensure an inductive behaviour of the load. It is also assumed that the load is approximately balanced.

9.3.3. Checking the correct connection of the CTs with a two channel scopemeter.

The first channel of the scopemeter must be connected to the phase voltage referenced to the neutral or tothe ground if the neutral is not accessible.The second channel must measure the associated current flowing from the network to the load as seen bythe CT input of the PQF.

99..33..33..11.. MMeeaassuurreemmeenntt ooff CCTT iinn pphhaassee LL11For the voltage measurement (channel 1), the positive (red) clamp must be connected to the phase L1 andthe negative clamp (black) must be connected to the neutral (ground).For the current measurement (channel 2), the clamp should be inserted into the wire connected on terminalX5.1 and the arrow indicating positive direction of the current should point towards the PQF. Do not forget toremove the short on the CT secondary before making the measurement.


45

L1

L2

L3Load sideSupply side

K L

k l

K L

k l

K L

k l

PQF

X5.2X5.3X5.4X5.5X5.6

X5.1

L1 L2 L3

Positive directionCh1 Ch2

N

N

Figure 9.2. Connection of the scopemeter for checking CT in phase L1.

On the scopemeter screen, two waveforms should appear. The voltage waveform should be approximately asine wave1 and the current waveform would normally be a well distorted wave because of harmonicdistortion. Usually, it is quite easy to extrapolate the fundamental component as it is the most important one(Figure 9.3).

I

I1

Figure 9.3. Extrapolation of fundmental component from a distorted waveform.

From the fundamental component of both signals, the phase shift must then be evaluated (Figure 9.4). Thetime ?T between zero crossing of the rising (falling) edge of both traces must be measured and converted toa phase shift ? by the following formula:

°∆

= 360*1TT

φ

where T1 is the fundamental period duration.For an inductive and non regenerative load, the current signal should lag the voltage by a phase shift lowerthan 90°.

1 If the earthing of the system is bad, the phase to ground voltage may appear like a very distorted waveform. In this case, it is better tomeasure the phase to phase voltage (move the black clamp to the phase L2) and substract 30° on the measured phase shift.


46

∆T

T1

U

I1

Figure 9.4. Phase shift evaluation between two waveforms.

99..33..33..22.. MMeeaassuurreemmeenntt ooff CCTT iinn pphhaassee LL22 aanndd LL33The same operations as those described in the previous paragraph must be repeated with the phase L2(Figure 9.5) and phase L3 (Figure 9.6).For a balanced load (which is usually the case in most of the three phase systems), the phase shift shouldbe approximately the same for all the three phases.

L1

L2


K L

k l

K L

k l

K L

k l

PQF

X5.2X5.3X5.4X5.5X5.6

X5.1

L1 L2 L3

Positive direction

Ch1 Ch2

N

N



47

L1

L2


K L

k l

K L

k l

K L

k l

PQF

X5.2X5.3X5.4X5.5X5.6

X5.1

L1 L2 L3

Positive direction

Ch1 Ch2

N

N


9.3.4. Checking the correct connection of the CTs with two current probes.If the main bus bar is available and all security rules are taken, it is possible to use the two channel scopemeter in order to see if the current measured through the CT is matching the real current in the bus.Connecting the current probes as shown on Figure 9.7., the two traces must be in phase and of the sameshape (the magnitude could be different as the gain are different) if the wiring is correct.

L1

L2


K L

k l

K L

k l

K L

k l

PQF

X5.2X5.3X5.4X5.5X5.6

X5.1

L1 L2 L3

Ch1 Ch2Positive direction

Positive direction

N

N

Figure 9.7. Connection of the scopemeter for checking CT in phase L1 by comparing the currents.

This operation has to be repeated for the remaining two phases for a complete check. The current probeshave to be changed accordingly.


48

9.3.5. Checking the correct connection of the CTs with a Fluke 41B.The Fluke 41B is a power analyser that allows measurements of one voltage and one current wave.Unfortunately, the device does not allow simultaneous display of both waveforms on the screen. But it ispossible to synchronise the triggering on either the voltage or on the current. All phaseshift measurementsare then referenced to the chosen origin. To read directly the phaseshift between the fundamentalcomponents, just select the spectrum window of the signal which is not chosen as the origin.The instrument must be configured in single phase measurements.The probes must be connected as shown on Figure 9.2, Figure 9.5 and Figure 9.6.

9.4. Step 4

Step 4: System set-up

9.4.1. With PQF-Prog

Once the PQF-Prog software has been successfully installed and your PC is properly connected (seechapter 8), select Programs in the Start menu and click on PQF. If you did not install PQF-Prog in theProgram Files directory, create a shortcut to PQF_Prog.exe.

After launching PQF-Prog, a text box indicating that Station 0 has been found will appear. Click ‘Done’. Youthen enter the PQF-Prog main Window.

In the Login box, type the User name and the password. Station must be “0”.

If you use the appropriate User name and password, four icons appear on the toolbar: Login, FilterOperation, Hardware set-up and Configuration.

Login

FilterOperation

Hardwareset-up

Configuration


49

If a wrong or no login is entered, you will only have access to the Login, Filter Operation and Configurationicons.

Click on the Hardware set-up icon.

In the hardware set-up window, you will have to specify:

• The network frequency• The grid nominal voltage (phase to phase)• The number of modules• The three lines CT ratio

Click on ‘apply’ to validate.

9.4.2. With the PQF-Manager

The 3 levels of the PQF-Manager are accessible from the window “Main menu”.To enter the “Main menu” window, press MENU.

Level 1 is for consulting, level 2 for filter programming and level 3 for commissioning.Select level 3 by pressing once the ? key.

Then press OK and enter the appropriate password for level 3.

The LED ‘SET’ will switch on.

In the hardware set-up window, you will have to specify:

• The network frequency• The grid nominal voltage (phase to phase)• The number of modules• The three lines CT ratio

9.5. Step 5

Step 5: Before switching the filter on

Before switching the filter ON, you have to ensure that all harmonics and reactive power compensation havebeen deselected. This can be done from the ‘Filter Operation’ menu of the PQF-Prog or level 2 of the PQF-Manager. Please refer to the detailed programming instructions of chapter 10.

MAIN MENU

Level 1Level 2

? Level 3?


50

9.6. Step 6

Step 6: Starting the filter

With all harmonics and reactive power compensation deselected, you can start the filter by pushing the RUNbutton of the master cubicle.

The main breaker should close within 30 seconds. One second after closing, the IGBT will start and the filterwill work under no load condition.

9.7. Step 7

Step 7: Stop the filter

Once the filter is connected to the network, stop it by pushing on the RESET button.

9.8. Step 8

Step 8: Start filtering

Once you have checked that the filter can connect to the network, you may start filtering and reactive powercompensation.

After programming the filter according to the procedure of chapter 10, you can switch the filter on by pushingthe RUN button.

A start-up sequence will then be conducted.

As represented on Figure 9.8, this sequence includes a network characterisation during which the filter maygenerated ‘musical’ sounds.

Figure 9.8. Start-up sequence

Start fan &preload

DC bus

Operation asprogrammed

Close MC

Start IGBT

Networkcharacterisation

Push RUN button

Start-up sequence


51

10. Operation

10.1. Normal working sequence

After successful commissioning (refer to chapter 9), the procedure to operate the active filter is:

1. From the OFF position (auxiliary and main contactor open, no light on), switch on the auxiliary breaker.If your PQFT system has more than two modules, the auxiliary breaker of slave cubicles should beswitched on before the one of the master cubicle.

2. After 20 seconds, the system will reset.

3. The auxiliaries are then on but the main contactor is still open.

The white light (ON) and the green one (OPEN) of the master cubicle are on, while the green light (OPEN) ofthe slave cubicles is on.

Master cubicle lights and buttons:

Slave cubicles lights:

If your PQFT is fitted with the PQF-Manager, the red LED ‘POWER’ is on.

CLOSE OPEN

RESET RUN LOC/REM ON CLOSE OPEN


52

4. Push the RUN button located on the master cubicle.

5. The filter then starts the start-up sequence:- Start fan and preload DC bus- Close main contactor- Start IGBT- Network characterization

During the start-up sequence, the red LED ‘START-UP’ of the PQF-Manager is on.

Once the main contactor is closed, the red light (CLOSED) of the master and slave cubicles becomes on,while the green light (OPEN) switches off.

Master cubicle

Slave cubicles:

LED n°3 of board A111 on the control rack should be red: it indicates that the PQF is properly synchronizedto the network (see illustration next page).

CLOSE OPEN




53

6. After the start-up sequence, the PQFT operates as programmed. The red LED ‘OK’ of the PQF-Managershould be on.

In the LED ‘FULL LOAD’ appears to be on, it only means that the filter cannot achieved the programmedrequirements. Refer to the chapter on programming with the PQF-Manager for more information.

7. Pushing the button RESET of the master cubicle causes the main contactor to open and to comeback at step 3 of this procedure.

The normal working sequence is represented on Figure 10.1.

A111 A112 A113 A119 A114 A115 A116 U100 U109DIG INT DSP GUI LIC LVI ALIM/GND ±15V +5V

YELLOW LEDGREEN LEDRED LED

1 2

3

21

3

21 21 21 1

21 1 2

3 4 3



54

Figure 10.1. Normal working sequence

OFF

20sec. Time delay

System reset

Auxiliaries ON

Start fan &preload

DC bus

Operation asprogrammed

Open MC

Close MC

Start IGBT


Switch on auxiliary breaker (Q101)

Push RUN button

Push RESET button

Start-up sequence


55

10.2. Additional installation instructions for the PQFT in presence of plaincapacitors

In some installations plain capacitors (without detuning reactors) coexist with harmonic producing loads.This situation is unadvicable given that the harmonics impose a very high stress on the capacitors as a resultof which their lifetime is greatly reduced. Moreover, due to the resonance condition created (by the capacitorand the predominantly inductive transformer and line impedance) high voltage distortion may be introducedwhich can cause other equipment in the plant to malfunction. Also the resonance amplifies the harmoniccurrent created by the loads as a result of which the feeders and transformers may be overloaded. For thesereasons ABB generally proposes to replace the plain capacitor by a detuned capacitor bank when highharmonic stress is present in the network.

In some active filter applications the commissioning engineer is faced with an installation where both anactive filter and plain capacitors are present. While this is an unadvicable and a technically unsoundsituation, ABB has acknowledged that in this case also the active filter should aim to give an optimalperformance. For this reason the control software of the filter incorporates a Stability Detection Program(SDP) that aims to increase the filter performance in this type of applications.

In installations where plain capacitors are present and cannot be changed to detuned capacitor banks,adhere to the recommendations below for optimal results:- Try to implement the installation given in Fig. 10.2 as opposed to the installation given in Fig. 10.3.

Feedingtransformer Filter CTs

Linear andnon-linear

loads

PQFx

Plain capacitorbank

Fig. 10.2. Proposed connection diagram for PQFx and plain capacitors.

Feedingtransformer Filter CTs

Linear andnon-linear

loads

PQFx

Plain capacitorbank

Fig. 10.3. Alternative for Fig. 10.2. when that connection approach cannot be implemented.

In Fig. 10.2, the capacitor bank is connected between the transformer and the filter CTs as a result of whichthe filter measures the pure load current. In Fig. 10.3 the filter measures also the capacitor bank current.While in the case of Fig. 10.3 the SDP will also work, it will be slightly less efficient since the influence of thecapacitors will be spread over a much wider frequency bandwidth. Harmonic filtering in the affectedbandwidth may be interrupted more often for parameter optimisation, this leading to a less optimal filteringperformance.

Ensure that the filter is in Mode 3 (see chapter 10, § 5)

10.3. Behavior in case of power outage

In case of power outage, the PQFT will stop and automatically re-start after having re-conducted the networkcharacterisation and synchronization procedures.


56

10.4. Buttons, lights and LED’s signification

10.4.1. Master cubicle.

• Push buttons:

RUN: starts the PQFTRESET: stops switching of the IGBTs and opens the main contactor.

• Local – remote switch: local or remote control of the filter. If remote is on, the push buttons are notoperational.

• Lights:

ON (white): the PQFT controller is connected to the supply (auxiliary breaker closed)CLOSE (red): the main contactor is closed (filter working)OPEN (green): the main contactor is open

Three light conditions are then possible:

ON (white) CLOSE (red) OPEN (green)No power connection (main contactor andauxiliary breaker open)Controller connected (auxiliary breakerclosed, main contactor open)

⊗ ⊗

Filter working (aux. breaker and contactorclosed)

⊗ ⊗

10.4.2. Slave cubicle

• Lights:

CLOSE (red): the main contactor is closed (filter working)OPEN (green): the main contactor is open


CLOSE OPEN


57

10.4.3. PQF-Manager

Red LED’s:

• POWER: the controller is connected to the supply (auxiliary breaker closed).

• START-UP: the PQFT is in the start-up sequence.

• OK: the PQFT is working properly and fulfilling programmed requirements.

• FULL LOAD: the filter is working at 100% of its nominal capacity and programmedrequirements are not fulfilled.

• ALARM: the filter has stopped due to an error.

• SET: the programming or set-up level of the PQF-Manager has been activated.

The PQF-Manager is also fitted with a screw to adjust contrast. This screw is situated on the back metalplate of the PQF-Manager.

10.4.4. Control rack.

Board A111 DIG LED 1 (green) on: OKLED 2 (red) on: malfunctionLED 3 (red) on: PQF synchronised on network

Board A112 INT LED 1 (green) on: OKLED 2 (red) on: malfunction

Board A113 DSP LED 1 (green) andLED 3 (yellow) blinking: OKLED 2 (red) on: malfunction

Board A114 LIC LED 1 (green) on: OKLED 2 (red) on: malfunction

Board A115 LVI LED 1 (green) on: OKLED 2 (red) on: malfunction


58

Board U109 LED 1 (green) on: OKLED 2 (red) on: power supply inhibitedLED 3 (red) on: output 1 inhibited

10.5. Programming with PQF-Prog

10.5.1. Filter operation principle.

The filter can have three types of effect on the network:

• Filter the selected harmonics until their magnitudes are close to zero (Maximum Filtering);• Filter the selected harmonics until their magnitudes reach the residual level permitted by the user

(Filtering to Curve);• Produce or absorb reactive power.

The user can put the emphasis on one of the above effects by selecting the filtering mode. The followingtable shows the three available modes:

Highest priority level Lowest priority levelMode 1 Filtering to curve Maximum filtering Reactive compensationMode 2 Filtering to curve Reactive compensation Maximum filteringMode 3 Filtering to curve Reactive compensation

A111 A112 A113 A119 A114 A115 A116 U100 U109DIG INT DSP GUI LIC LVI ALIM/GND ±15V +5V

YELLOW LEDGREEN LEDRED LED

1 2

3

21

3

21 21 21 1

21 1 2

3 4 3


59

In Mode 1, the PQFT will first filter to the pre-programmed curve. Once the requirements are fulfilled,remaining resources will be allocated to reducing the selected harmonics as close as possible to zero. Iffurther resources are then available, reactive power compensation will be performed as required.

In Mode 2, the second priority after filtering to the curve is reactive power compensation. Maximum filteringcomes in third place.

In Mode 3, two levels are defined: filtering to curve and reactive power compensation.

In any case, filtering to curve is always the first priority. The alarm contact is activated (open) if the filtering tocurve requirements are not fulfilled.

Figure 10. here after illustrates the principle of filtering to curve for one particular harmonic order. Theflexibility of the PQFT control is such that a specific curve may be defined for each selected harmonic.

Figure 10.4. Filtering to curve for harmonic order n

The programming procedure consists in:

1) Defining the Mode of operation.

2) Specifying the harmonics to be filtered and the permitted residual level (=curve) for each of them. At 50Hz, 20 harmonics between the 2nd and 50th may be selected. At 60 Hz, 15 harmonics between the 2nd

and 50th.

3) Programming reactive power compensation parameters

10.5.2. Starting

Once the PQF-Prog software has been successfully installed (see chapter 7), select Programs in the Startmenu and click on PQF. If you did not install PQF-Prog in the Program Files directory, create a shortcut toPQF_Prog.exe.

After launching PQF-Prog, a text box indicating that Station 0 has been found will appear. Click ‘Done’. Youthen enter the PQF-Prog main Window.

Filtered current

Remainingcurrent

Before filtering After filtering

Permittedresidual level

=curve

Load currentfor harmonicorder n


60

In the Login box, type the User name and the password. Station must be “0”.

If you use the appropriate User name and password, four icons appear on the toolbar: Login, FilterOperation, Hardware set-up and Configuration.

If a wrong or no login is entered, you will only have access to the Login, Filter Operation and Configurationicons.

Login

FilterOperation

Hardwareset-up

Configuration


61

10.5.3. Programming the filter

Step 1: click on the Filter Operation icon.

Step 2: Select the Filter Mode tab.

Step 3: Select the option button corresponding to your chosen mode of operation. The priorities of theselected mode are indicated at the bottom of the window.

Click on ‘Ok’ if you wish to save your choice and leave the Filter Operation mode. Click on‘Apply’ if you wish to validate your choice and stay in Filter Operation mode.

Step 4: Select the Harmonics tab.

In order to select a harmonic order, enter Y (yes) in the second column. N (no) indicates thatthe corresponding harmonic has not been selected.The curve may be programmed in absolute terms (Amps), in % of the fundamental current orin % of the rms current.After choosing your appropriate reference by using the option button, program your target inthe third column for the harmonics you have selected. The values there entered constitutethe curve and the first priority of your PQFT will be to filter harmonics until each selectedorder becomes lower than its specified target.

Click on ‘Ok’ if you wish to save your choice and leave the Filter Operation mode. Click on ‘Apply’ if you wishto validate your choice and stay in Filter Operation mode.


62

Step 5: The filter may be switched on or off from the On/off tab.

10.6. Programming with PQF-Manager

10.6.1. Filter operation principle.

The filter can have three types of effect on the network:

• Filter the selected harmonics until their magnitudes are close to zero (Maximum Filtering);• Filter the selected harmonics until their magnitudes reach the residual level permitted by the

user (Filtering to Curve);• Produce or absorb reactive power.

The user can put the emphasis on one of the above effects by selecting the filtering mode. The followingtable shows the three available modes:

Highest priority level Lowest priority levelMode 1 Filtering to curve Maximum filtering Reactive compensationMode 2 Filtering to curve Reactive compensation Maximum filteringMode 3 Filtering to curve Reactive compensation

In Mode 1, the PQFT will first filter to the pre-programmed curve. Once the requirements are fulfilled,remaining resources will be allocated to reducing the selected harmonics as close as possible to zero. Iffurther resources are then available, reactive power compensation will be performed as required.

In Mode 2, the second priority after filtering to the curve is reactive power compensation. Maximum filteringcomes in third place.

In Mode 3, two levels are defined: filtering to curve and reactive power compensation.

In any case, filtering to curve is always the first priority. The alarm contact is activated (open) if the filtering tocurve requirements are not fulfilled.


63

Figure 10.5. here after illustrates the principle of filtering to curve for one particular harmonic order. Theflexibility of the PQFT control is such that a specific curve may be defined for each selected harmonic.

Figure 10.5. Filtering to curve for harmonic order n

The programming procedure consists in:

1) Defining the Mode of operation.

2) Specifying the harmonics to be filtered and the permitted residual level (=curve) for each of them. At 50Hz, 20 harmonics between the 2nd and 50th may be selected. At 60 Hz, 15 harmonics between the 2nd

and 50th.

3) Programming reactive power compensation parameters

10.6.2. Keys identification.

Filtered current

Remainingcurrent

Before filtering After filtering

Permittedresidual level

=curve

Load currentfor harmonicorder n

Numericalkeypad

Arrowbuttons

‘OK’button

‘MENU’button

Deletebutton


64

10.6.3. Programming the filter.

Step 1: The 3 levels of the PQF-Manager are accessible from the window “Main menu”.To enter the “Main menu” window, press MENU.

Level 1 is for consulting, level 2 for filter programming and level 3 for commissioning.Select level 2 by pressing once the ? key.

Then press OK and enter the appropriate password for level 2.

The LED ‘SET’ will switch on.

Step 2: Three options appear in the level 2 window: mode, harmonics and Q compensation.Select Mode by using the ? key.

Press OK.

Step 3: Select your preferred mode of operation with the ? key. The priorities of the selected modeare indicated on the window.

MAIN MENU

Level 1? Level 2?

Level 3

LEVEL 2

? Mode?HarmonicsQ compensation

FILTER MODE

MODE 1 2 3

FILTERING TO CURVEQ COMPENSATIONMAX FILTERING

FILTER MODE

MODE 1 2 3

FILTERING TO CURVEMAX FILTERINGQ COMPENSATION


65

The selected mode only becomes operational once you press the OK button.

Step 4: Press on ‘MENU’ to come back to level 2 main window, select ‘harmonics’ by using the ?key and press OK.

In the next window, you have to specify the unit in which the permitted residual level (=curve) is expressed. Three possibilities are offered: amps ’A’, percentage of the fundamentalmagnitude ’%I1’ and percentage of the RMS current ’%Irms’.Make your choice with the ? key and press OK.

You will then enter in the Harmonics window.

HARMONICS

CURVE : AORDER SELECT CURVE

5 Yes 107 No 711 Yes 5

Use the ? ? keys to select an order and press ‘OK’ to activate the corresponding line.

Once the line is activated, you may modify the order number by using the DEL button todelete the current value and the numerical keypad of the PQF-Manager to enter the newvalue.

Press ‘OK’ to activate the Select column of the line. Use the ? button to switch between‘Yes’ and ‘No’.

Press ‘OK’ to activate the Curve column of the line and use the numerical keypad to enteryour filtering objective.

Once your parameters are entered, press ‘OK’ to activate your programming for thecorrespondent harmonic order.

FILTER MODE

MODE 1 2 3

FILTERING TO CURVEQ COMPENSATION

LEVEL 2

Mode ? Harmonics ?

Q compensation


66

You can select and programme each individual harmonic by using the ? ? keys andfollowing the same procedure.

Step 5: Press on ‘MENU’ to come back to level 2 main window, select ‘Q compensation’ by using the? key and press OK.

In the first window, you have to specify whether reactive power compensation is requested.Use the ? key to make your choice and press ‘OK’ to validate.

If ‘ON’ is selected, you have to specify the type of reactive power compensation: static ordynamic. Use the ? key to make your choice and press ‘OK’ to validate.

If you select static compensation, you have to specify the amount of fixed reactive power(kvar) that is requested. A positive value means a capacitive injection while a negative valuemeans an inductive consumption.

If you select dynamic compensation, you have to specify the target cos ϕ in the range 0.6inductive to 0.6 capacitive.

LEVEL 2

ModeHarmonics

? Q compensation ?

Q COMPENSATION

Q COMP: OFF

Q COMPENSATION

Q COMP: ONQ COMP: STEADYQ : 50

Q COMPENSATION

Q COMP: ON Q COMP: DYNAMICTARGET : 0.96


67

Press ‘ON’ to activate your choice.

Step 6 Return to the main menu by pressing the ‘MENU’ button.

10.7. PQFT and network monitoring with the PQF-Manager

The 3 levels of the PQF-Manager are accessible from the window “Main menu”.To enter the “Main menu” window, press MENU.

Level 1 is for consulting, level 2 for filter programming and level 3 for commissioning.

Select level 1 by using once the ? key.

Then press OK.

The consulting level gives you access to 4 submenus: the filter status, the network status, the waveform andthe spectrum.To select one of those submenus, use the ? key and press OK.

10.7.1. Filter status.

In the Consulting level window, select Filter status and press OK.

A horizontal bar graph appears. It depicts the percentage of the filter capabilities used as represented onfigure 10.6.

MAIN MENU

? Level 1?Level 2Level 3

LEVEL 1

? Filter status?Network statusWaveformSpectrum


68

0% 100%75%

Figure 10.6. Filter Status Window

If you press the ? key, you display a second window listing the value of each limiting factor:- The percentage of use of the DC voltage capability;- The percentage of use of the peak current capability;- The percentage of use of the RMS current capability;

This second window also displays the error code if applicable.

You can easily switch between the 2 Filter Status windows with the ? ? keys.

To come back to the Consulting level menu from any of those windows, press MENU.

10.7.2. Network status

In the Consulting level window, select Network status and press OK.

The following window appears:

NETWORK STATUS

U1-2 = 396 VI1 = 654 ATHDU1 = 17 %THDI1 = 74 %

Figure 10.7. Network Status

It gives you the RMS voltage between L1 and L2, the RMS current in L1 as well as the Total HarmonicDistortion on the same voltage and current.

By pressing the ? key, you enter the second window displaying the RMS voltage between L2 and L3, theRMS current in L2 as well as the Total Harmonic Distortion on the same voltage and current.

LEVEL 1

Filter status ? Network status?

WaveformSpectrum


69

If you press once more the ? key, you enter the third and last window with the values of the RMS voltagebetween L3 and L1, the RMS current in L3 as well as the Total Harmonic Distortion on the same voltage andcurrent.

You can easily switch between those 3 windows with the ? ? keys.

Press MENU and you come back to the consulting level menu.

10.7.3. Waveform

In the Consulting level window, select Waveform and press OK.

The first Waveform window proposes a choice of 3 submenus: the network voltage, the line current and thefilter current. Select the waveform you want to display with the ? key and press OK.Before displaying the waveform, you still have to choose the phase you want to visualise. You can makeyour selection in the next window with the ? key and you validate by pressing OK.You then see the waveform you have selected.

Un2(V)

512

-512

Figure 10.8. Waveform Window

The graph indicates the unit, the waveform as well as the maximum positive and negative values of thescale.

Press MENU and you come back to the Consulting level MENU.

LEVEL 1

Filter statusNetwork status

? Waveform ?Spectrum


70

10.7.4. Spectrum

In the Consulting level window, select Spectrum and press OK.

The first Spectrum window proposes a choice of 3 submenus: the network voltage, the line current and thefilter current. Select the spectrum you want to display with the ? key and press OK.Before displaying the spectrum, you still have to choose the phase you want to visualise. You can make yourselection in the next window with the ? key and you validate by pressing OK.You then see the spectrum you have selected.

60 AH: 015 A

In1

Figure 10.9. Spectrum Window

The graph indicates the maximum value of the scale. In the above right corner, you have the rank (0 is forDC) and the value in amps for the harmonic identified with the arrow (? ).

Press the ? or ? key to shift your selected harmonic of one order. If you want to move faster in thespectrum, you can use the ? or ? key. You will then shift of 15 orders.

Press MENU and you come back to the Consulting level MENU.

LEVEL 1

Filter statusNetwork statusWaveform

? Spectrum ?


71

10.8. Remote control and alarm contact

10.8.1. Remote control

The PQFT may be switched on and off from a remote location.

The remote switch has to be connected to connection points X12-3 and X12-4 of terminal marked X12.The remote/local switch of the master cubicle door has to be switched in remote position.The remote signal voltage is 24Vdc:X12.3 (+24Vdc)X12.4 (0V)

Note: once remote is on, the push buttons of the door are not operational anymore.

10.8.2. Alarm contact

The PQFT is fitted with a normally open alarm contact (voltage free contact) allowing remote supervision ofthe unit. It is activated (open) if one of the following conditions is met:

• The filter is in error condition• The filter is off• The filter is working properly but not able to filter to the pre-defined level

(hardware limitation)

When it is closed the filter is working properly and all filtering requirements are fulfilled.

The exterior alarm has to be connected to connection points X12-1 and X12-2 of terminal X12.

10.9. Protections

The PQFT is fitted with two types of protection:• Slow protection• Fast protection

The role of the slow protection is to change on-line the way the filter is working according to the filter stressand programmed. This ensures that the filter is never overloaded and always has an optimal filtering effect.

The fast protection is only activated in case of abnormal working conditions and ensures the integrity of thefilter.

The fast protection means include:

• Protection fuses.

• Blocking system of the IGBT bridge in case of:• AC overvoltage on the mains• DC overvoltage on the DC bus• Filter over current• IGBT over current• IGBT over temperatureIf an error persists, the main breaker will also react.

• Short-circuit or overcurrent (peak & thermal) protection inside the IGBTs



72

11. Fault handling and troubleshooting

11.1. Fault handling

11.1.1. Type of faults

Faults are classified into two basic families:

• Minor faults

• Critical faults

Immediately after the fault occurrence, the error is cleared. If it has disappeared, the fault is said minor. Inthe other case, the fault is considered as critical.

11.1.2. Fault handling and fault clearance procedure

After the occurrence of a fault, the IGBT’s are stopped and the filter determines the type of fault it is facing.If it is not critical, IGBT’s are restarted and the filter is back to normal operation.If the fault is critical, it is memorised and the filter conducts a fault clearance procedure.

Fault handling procedure:

The fault clearance procedure starts with the opening of the power circuit breaker. The system is reset andthe filter conducts a modified start-up sequence as shown hereafter.

Normaloperation

Stop IGBT

Fault occurrence

Critical fault?

Memorise fault

Fault clearanceprocedure

Start IGBT

YN


73

Modified start-up sequence for fault clearance:

If within 30 seconds after the re-start of the IGBT’s no critical fault occurs, the initial fault is cleared and thefilter comes back to normal operation.

If a critical fault occurs during those 30 seconds, either it is a different fault than previously and a new faultclearance procedure is conducted or it is the same fault.If it is the same fault, a fault clearance procedure will be re-conducted until the same fault is detected 5consecutive times.In this case, the power breaker is open, the filter definitively stopped and the error code is displayed on thePQF-Manager if installed.

This procedure is shown in the next page.

Start fan

Delayfor 10s

PreloadDC bus

Close MC

Start IGBT



74

Sys

tem

res

et

Sta

rt-u

pse

qu

ence

Cri

tica

l fau

lto

ccu

rren

ce w

ith

in 3

0s?

Mem

ori

sefa

ult

Faul

t cl

eara

nce

pro

ced

ure

Fau

lt c

lear

ed

YN

Op

en M

C

Nor

mal

op

erat

ion

Sam

e fa

ult

as b

efo

re

5th

su

cces

sive

f

ault

?

Faul

t cl

eara

nce

pro

ced

ure

Def

init

ive

sto

p

Dis

pla

y er

ror

mes

sag

eo

n P

QF

-Man

ager

Op

en M

C

N

N

Y

Y

D

isp

lay

fau

lt m

sg (P

QF

Man

ager

)

Ala

rm O

N


75

11.2. Troubleshooting

11.2.1. Frequent problems occurring at commissioning stage

Problems occurring at commissioning stage are mainly due to wrong CT connection or CT bridges notremoved. Check carefully those connections in accordance with the commissioning procedure.

FAULT Possible causes SolutionsNo filtering nor reactivepower compensation

- All CT’s are in correctphases but some arereversed

- Wrong phase rotation- CT bridges not removed

- Check carefully CT wiring- Remove CT bridges on

CT secondary and PQFTterminal input

No dynamic reactive powercompensation

All CT’s are in correct phasesbut all are reversed

- Modify CT connectionaccordingly, or

- Reversed CT’s may becorrected by software: anegative CT ratio has tobe specified.

11.2.2. Error codes and messages

After a filter trip, an error message is displayed on the PQF-Manager. At the same time, the correspondingerror code is stored in the filter controller’s permanent memory. The error codes can be accessed by PQF-Prog users that have the appropriate password such as ABB service personnel. Below is explained how theerror messages can be accessed with the PQF-Manager. If your filter is not fitted with this option, contactyour ABB service provider for further support.

In order to access the error code in the PQF-Manager, press MENU to access the “Main menu” window.

Select level 1 by using once the ? key.

Then press OK.Select the filter status submenu with the ? key and press OK.

Display the ? key to display the error message.

MAIN MENU

? Level 1?Level 2Level 3

LEVEL 1

? Filter status?Network statusWaveformSpectrum


76

Error code Error message Possible causes Actions1 IGBT fault - Too high IGBT temperature

(thermal protection)- Too high instantaneous

current level (short-circuitprotection)

- Supply voltage of IGBTdrivers too low

- Visual inspection of IGBT bridge- After checking bridge condition, push

on the ‘RESET’ button of the door. Ifthe red LED on the IGBT dominoboard remains on, contactimmediately your ABB serviceprovider

- Check rotation of fan.2 Filter over-current Too high output current of the

filter (short-circuit protection)- Inspect IGBT bridge

3 AC overvoltage Grid voltage rises tounacceptable levels

Measure AC RMS voltage for the threephases and check if it is within limits

4 DC overvoltage DC voltage on DC busreaches unacceptable levels

- Check DC capacitorsInspect visually DC voltage dividerand wiring

5 Connection fault - Flat cable between thecontrol rack and IGBTdriver is disconnected orwrongly connected.

- Module number setting onboard A112 does notcorrespond to the numberof modules really present.

- The jumpers on the lastdomino board are missingor are on the wrongdomino.

- Check flat cable connections- Verify that only the domino board of

the last power module is fitted withjumpersCheck the number of modules set onthe controller board A112

6 Power supply fault One of the auxiliary powersupplies is out of service.

- Check that no red LED is on thecontrol rack (except LED 3 of A111).If yes, call your ABB serviceprovider.

- Check fuses of power supplies7 Control board fault The microcontroller is not

working properly.Contact immediately your ABB serviceprovider.

8 CAN bus fault The internal communicationbus of the PQFT is notworking properly.

Contact immediately your ABB serviceprovider.

16 DSP pgmcorrupted

DSP program corrupted Contact immediately your ABB serviceprovider.

32 Watchdog timeout Software in unpredictablestate.


64 Soft DCovervoltage T

DC voltage on DC bus is toohigh.

- Check if all connectors on theelectronic rack are plugged inproperly.

- Check the DC voltage boards.65 Soft DC

overvoltage BDC voltage on DC bus is toohigh.


- Check the DC voltage boards.66 Soft DC

undervoltage TDC voltage on DC bus is nothigh enough.


- Check the DC voltage boards.- Check the main contactor (K10)

control circuit wiring and signalwiring.

- Check the balancing resistors on theIGBT power module.


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Error code Error message Possible causes Actions67 Soft DC

undervoltge BDC voltage on DC is not highenough.


- Check the DC voltage boards.- Check the main contactor (K10)

control circuit wiring and signalwiring.

- Check the balancing resistors on theIGBT power module.

96 Soft DCovervoltage

DC voltage on DC bus is outof normal range (overvoltage)

- Inspect visually DC voltage dividerand wiring

97 Soft DCundervoltage

DC voltage on DC bus is outof range (undervoltage)

- Inspect DC voltage measurementcircuit

98 Soft ACundervoltage

AC voltage is out of range(undervoltage)

- Check network voltages on threephases voltage

- Check AC measurement circuit99 Soft synchro fault The system desynchronises

from the network- Check phase rotation order of filter

supply- Check network frequency and

variation to see one withinacceptable limits

- Check voltage level of the supplysystem

112 Preload timeout The preloading of the DC bustakes an abnormally longtime.

Check preloading circuit system.

113 DSP stoppedsystem

DSP decision to stop thesystem.


114 Main breaker trip - Power breaker not closedafter being energised

- Undervoltage on AC grid

- Check auxiliary contact of mainbreaker and associated circuit

- Check that grid AC voltage is highenough (within tolerance)

115 DSP bus fault The DSP has stoppedcommunicating


116 EEPROMcorrupted

Internal memory corrupted Contact immediately your ABB serviceprovider.

117 PWM fault Internal timing problem Contact immediately your ABB serviceprovider.

11.2.3. Faults not related to error codes

• Unstable filter.Check CT connection and the presence of plain capacitors. Bear in mind that harmonics below theresonance frequency of capacitor banks must be deselected (see chapter 10).

• Filter tripping during network characterization.In weak networks, it may happen that high harmonic orders could not be characterized. Those orders shouldbe deselected.

• No display on PQF-Manager.Adjust the contrast of the PQF-Manager. Open the front door of the PQFT (main breaker open, auxiliaryclosed) and adjust the contrast screw located on the back metal plate of the PQF-Manager.

• No LED is on on boards A116, U109 (power supplies).Remove the board and check fuse(s) condition. Replace them if needed.


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11.2.4. Restarting the filter after fault correction

• Press RESET button 2 times.• Press RUN button.

The filter will then start its start-up sequence and will attempt to work again.


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12. Maintenance

Although your PQFT has been designed for minimum maintenance, the following procedure should becarefully followed to insure the longest possible life to your investment.

WARNING!

All maintenance work described in this chapter should only be undertaken by a qualified electrician. TheSafety Instructions section of this manual must be thoroughly followed.

12.1. Maintenance frequency

Under normal working conditions and environment, maintenance every six months is recommended.

In case of installation in a dirty or sandy environment, a more frequent maintenance programme should beimplemented.

12.2. Maintenance procedure

Step 1 Shut the filter down by pushing the ‘RESET’ button of the door cubicle.Open the auxiliary circuit breaker.Wait at least 15 minutes for the discharge of DC capacitors.

Step 2 CleaningAll dust deposits have to be removed from all parts, especially the heatsink and fan.Indeed,the heatsink picks up dust from the cooling air and The PQFT might run intoovertemperature faults if the heatsink is not cleaned regularly.

Step 3 Check breakers condition

Step 4 Check tightness of all electrical connections

Step 5 Check condition of discharge resistor on power modules

Step 6 Check ambient temperature and equipment ventilation operation.

Step 7 Restart the PQFT according to commissioning procedure.

12.3. Fan

The cooling fan lifespan is about 5 years, depending on usage and ambient temperature.Fan failure is often preceeded by increasing noise from the bearings and rise of the heatsink temperaturedespite cleaning. It is recommended to replace the fan once these symptoms appear.


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12.4. Capacitors reforming

If the filter has been non-operational for more than one year, DC capacitors must be reformed (re-aged)before use. Without reforming, capacitors may be damaged at start-up.

Stocked or non-operational filters should be reformed once a year. The method indicated below assumesthat the filter is stocked in a clean and dry environment.

To reform the capacitors, switch the power on for about 2 hours, with all harmonics and reactive powerdeselected.

If the filter has been left more than 2 years without operation, please contact your ABB service provider.

Asea Brown Boveri Jumet S.A.Zoning Industriel de JumetB-6040 Charleroi, BelgiumPhone : +32 71 250 811Fax : +32 71 344 007

This product has been certified by ABB Group as IndustrialIT

EnabledTM - Information Level. All product information is supplied ininteractive electronic format, based on ABB Aspect ObjectTM

technology.The IndustrialIT commitment from ABB ensures that every enterprisebuilding block is equipped with the integral tools necessary to install,operate, and maintain it efficiently throughout the product lifecycle.

While all care has been taken to ensure that the informationcontained in this publication is correct, no responsibility can beaccepted for any inaccuracy. The Company reserves the right toalter or modify the information contained herein at any time in thelight of technical or other developments. Technical specifications arevalid under normal operating conditions only. The Company does notaccept any responsibility for any misuse of the product and cannot beheld liable for indirect or consequential damages. 2G

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Instructions Manual Power LV Active Filter PQFT · 1. Safety instructions These safety instructions...

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Transcript of Instructions Manual Power LV Active Filter PQFT · 1. Safety instructions These safety instructions...