MODELING AND SIMULATION OF DYNAMIC VOLTAGE RESTORER · PDF fileMODELING AND SIMULATION OF...

FUTO Journal Series (FUTOJNLS) 2015 VOL 1 Issue 1 50

Uzoechi et al Modelling and Simulation of Dynamic

MODELING AND SIMULATION OF DYNAMIC VOLTAGE

RESTORER FOR POWER QUALITY IMPROVEMENT

Uzoechi LO

and Obiakor CM

Department of ElectricalElectronic Engineering

Federal University of Technology Owerri Nigeria lazarusuzoechifutoedung

Abstract

In this paper the power quality was improved by modeling and simulation of Dynamic Voltage Restorer

(DVR) DVR is a power electronic device that can protect sensitive loads from various disturbances in

the power supply This paper modeled and simulated the Dynamic Voltage Restorer to mitigate three

major power quality problems namely voltage sag voltage swell and harmonic distortion for power

quality improvement To solve these problems Custom Power Devices are used and one of these devices

is DVR which is the most effective and efficient custom power devices used in distribution network for

power quality improvement DVR is a series compensating device that injects voltage of desired

magnitude and frequency in series and in synchronism with the distribution supply voltage to restore the

load voltage to a desired voltage level This is implemented using MATLABSimulinkSimPowerSystem

The DVR improved the voltage to about 95-98

KeywordsmdashDynamic Voltage Restorer (DVR) Voltage sag Voltage swell Harmonics Power quality

Custom Power Device

1 INTRODUCTION

The quality of power output delivered from

the utility to the consumers has become a major

concern in the restructured power system

Therefore power quality (PQ) is a major

constraint and a vital measure of an electrical

power system The importance of improved power

quality has risen very considerably over the last

two decades due to a remarkable increase in the

number of modern industrial equipment which are

mostly based on electronic devices They include

programmable logic controllers and other

electronic components that are very sensitive to

power disturbance or problems which if not

controlled and corrected can cause a very big

harm to them (Lalitha and Vindhya 2013)

Ideally the power generated at the power

station is purely sinusoidal in nature and of high

power quality where the purely sinusoidal current

waveform is in phase with the purely sinusoidal

voltage waveform and at a magnitude and

frequency given by the national standards or

system specification (Kavitha et al 2013) and

(Roncero-Sanchez et al 2009) But due to the

presence of connected non-linear loads

unbalanced loads power system faults and power

electronic converters in the power system the

power waveform is distorted and becomes non-

sinusoidal thereby leading to poor power quality

problems such as voltage sag voltage swell

surge harmonic distortion overvoltage

undervoltage flickers and blackout (Reddy and

Anyaneyulu 2001) and (Afonson et al 2010)

Consequently these power quality problems can

lead to increase in power losses power system

collapse malfunction data loss and damage of

equipment There is a need to protect our electrical

and electronic equipment from malfunctioning or

damage as a result of presence of power quality

problems in our power supply system This can be

achieved by improving the quality of power

supply being delivered to the consumers which

can be implemented by using Power Improvement

devices One of them is the Dynamic Voltage

Restorer (DVR) and by virtue of its fast dynamic

response is the most effective and efficient

(Mallela et al 2005)

The DVR is a series connected device which

by voltage injection can control the load voltage

(Nielsen 2002) The three major operations of



DVR are the compensation for voltage sag

voltage swell and harmonic distortion Earlier

power quality improvement started on the

generation and transmission system where

Flexible AC Transmission System (FACTS)

devices were used which include STATCOM ndash

Static Synchronous Compensator SSSC ndash Static

Synchronous Series Compensator IPFC ndash

Interline Power Flow Controller UPFC ndash Unified

Power Flow Controller (Pandey 2013) But these

FACTS devices were for transmission system

only However in the distribution system today

it is a major focus for power quality improvement

and also due to the disadvantages attached to

FACTS devices such as fixed compensation

bulkiness and electromagnetic interference These

urged the power system and power electronic

engineers to think of developing an adjustable and

dynamic solution and led to the modification of

the FACTS devices for use in the distribution

system so that power quality can be further

improved These modified devices are called

Custom Power Devices which include Distributed

Static Compensators (DSTATCOM) Dynamic

Voltage Restorer (DVR) Uninterruptable Power

Supply (UPS) Static Var Compensator (SVC)

Among these devices DVR is the most effective

and efficient custom power device because of its

low cost smaller size fast response towards the

disturbance and most importantly its dynamism

makes it possible to inject only the quantity or

amount of voltage required at a particular time

(Nielsen 2002)

The DVR is still a modern device which

insertion and use in the grid system is still rare

(El-Gamma et al 2011) DVR was treated in

(Nguyen and Saha 2004) and (Jena et al 2012)

where the analysis was based on voltage sag

mitigation only They did not provide solution for

protection against other power quality problems

like voltage swell harmonic distortion Also the

work in (Tumay et al 2011) dealt with DVR for

rectifying the problem of voltage sag only as they

considered voltage sag to be the most severe since

sensitive loads are very susceptible to temporary

changes in voltage In the paper (Benachaiba and

Ferdi 2008a) DVR was designed for hharmonics

distortion compensation and in this work voltage

sag and swell were not treated or considered

Also in the work in (Lalitha and Vindhya 2013)

controller based on repetitive control for a DVR to

compensate voltage sag harmonic voltage and

voltage imbalance was discussed The research in

(Vivek and Srividhya 2013) was aimed at getting

good quality of power and minimizing the power

tariff achieved by implementing hybrid power

generation system but focused on the various

methods of power quality improvement

techniques in hybrid power system

However observation showed that most of

these aforementioned works provided limited

information about the comprehensive operation

and detailed description of the modelling design

control and simulation aspects

This paper analyses power quality and its

associated problems and subsequently presents a

concise comprehensive information on the

descriptive modeling simulation and operation of

DVR for the mitigation of voltage sag voltage

swell and harmonic distortion in the distribution

power system

11 POWER QUALITY AND ITS

PROBLEMS

Power Quality problems involve variation in

voltage magnitude variation in frequency and

variation in waveform shape (harmonics)

The problems of Power Quality can be categorized

as

ii Short-duration power quality disturbances ndash

which include voltage sag voltage swell and

voltage transient (impulsesurge)

iii Long-duration power quality disturbances ndash

which include overvoltage and undervoltage

iv Continuous and steady-state power quality

disturbance ndash which include harmonic

flickers and voltage imbalance (Benachaiba

and Fredi 2008b)



111 Voltage Sag

According to IEEE defined standard (IEEE

Std 1159-1995) (IEEE Standard Board 1995)

ldquoVoltage Sag is defined as a decrease in rms

voltage from 09 to 01 per unit (pu) for a duration

of 05 cycle of power frequency to 1 minuterdquo

Also Voltage sag can be defined as ldquoa short

reduction in rms voltage magnitude from 90 to

10 of nominal voltage for a time greater than

05cycle of power frequency but less than or equal

to 1minutes (Pante and Kristina 2008) The

characterization of voltage sag is related with the

magnitude of remaining voltage during sag and

the duration of sag as shown in Fig11

Fig11 Voltage waveform during voltage sag (Benachaiba and Ferdi 2008b)

Voltage Sag can be classified based on the sag

magnitude and duration According to IEEE std

1159-1995 (IEEE Standard Board 1995 they are

classified as shown in the Table 11

Voltage sag may be caused by short-circuit

fault and earth fault in the power network starting

up of heavy induction motor of large current

rating long distance transmission and distribution

and unbalance load on a three phase system

(Lalitha and Vindhya 2013) and (IEEE Standard

Board 1995 Also the effects of voltage sag can

be observed in the malfunction or damage of

sensitive equipment reduction in energy transfer

of electric motors industrial processes being

brought to standstill power system failure or

collapse overheating of electrical equipment and

decrease in economy (Lalitha and Vindhya 2013)

and (Pandey 2013)

112 Voltage Swell

According to IEEE defined standard (IEEE Std

1159-1995) (IEEE Standard Board 1995

ldquoVoltage Swell is defined as a increase in rms


Type of Sag Duration Magnitude

Instantaneous 05 ndash 30 cycles 01 ndash 090 pu

Momentary 30 cycles ndash 3s 01 ndash 090 pu

Temporary 3s ndash 1 min 01 ndash 090 pu

Table 11 Voltage sag duration and

magnitude





increment in rms voltage magnitude from 110

to 190 of nominal voltage for a time greater than


to 1 minutes (Pante and Kristina 2008) Voltage

swell is as shown in Fig12

Fig 12 Voltage waveform during voltage swell

(Benachaiba and Fredi 2008b)

113 Harmonic Distortion

This is a power quality problem caused by non-

linear equipment as a result of their distortion of

the power waveform (Lalitha and Vindhya 2013)

The current of these non-linear loads as shown in

Fig 13 contains harmonics which produces a

non-linear voltage drop in the line impedance

which distorts the load voltage (Afonson et al

2010) The presence of harmonics in power lines

causes greater power losses in the distribution

system interference problem in the

communication system overheating and pulsing

torque in rotating machinery and operation failure

of electronic equipment (Afonson et al 2010)

Fig13 Diagrammatical representations of

harmonic distortion (Afonson et al 2010)

2 DYNAMIC VOLTAGE RESTORER

DVR is a power electronic device that can

protect sensitive loads from various disturbances

in the power supply It is a series compensating

interfaced equipment between the utility and

customer connected in series between supply and

load to mitigate three (3) major power quality

problems which are voltage sag voltage swell and

harmonic distortion (Mallela et al 2005) There

are numerous reasons why DVR is preferred over

other devices (Haque 2011) Although SVC

predominates the DVR but the latter is still

preferred because the SVC has no ability to

control active power flow DVR is smaller in size

power efficient and less expensive too An

advanced DVR can be achieved by integrating

present DVR with Active Power Filter(APF) in

other to additionally include filtering of

harmonics as a result of non-linear loads in

system Fig 21 shows the placement of DVR in

the distribution system



21 Basic Component and Configuration Of

DVR

The general configuration of DVR consists of the

energy storage unit inverter unit control unit

filter unit series injection transformer unit DC

charging unit and protection unit as shown in

Fig22

Fig 22 Different modules that make up a typical DVR (Tumay et al 2011)

The main function of these energy storage

units is to provide the desired real power during

voltage sag Various devices such as Lead acid

batteries Superconducting Magnetic Energy

storage (SMES) and Super-Capacitors can be used

as energy storage devices The amount of active

power generated by the energy storage device is a

key factor as it decides the compensation ability

of DVR (Li et al 2001) The voltage source

inverter (VSI) converts this DC voltage into an

AC voltage In order to boost the magnitude of

voltage during sag in DVR power circuit a step

up voltage injection transformer is used Thus a

VSI with a low voltage rating is sufficient (Li et

al 2001) Generally Pulse-Width Modulated

Voltage Source Inverter (PWMVSI) is used

To convert the inverted PWM pulse waveform

into a sinusoidal waveform low pass passive

filters are used In order to achieve this it is

necessary to eliminate the higher order harmonic

Fig21 Typical DVR in Distribution System with sensitive Load (Kavitha et al 2013)



components during DC to AC conversion in VSI

which will also distort the compensated output

voltage We can avoid higher order harmonics

from passing through the voltage transformer by

placing the filters in the inverter side Thus it also

reduces the stress on the injection transformer (Li

et al 2001) If there is a fault current due to fault

in the downstream it will flow through the

inverter In order to protect the inverter a By-pass

switch is used (Li et al 2001) The three phase

injection transformer is used to inject the missing

voltage to the system Also the transformer serves

the purpose of isolating the DVR from the power

system The charging circuit has two main tasks

They are to charge the energy source after a sag

compensation event and to maintain DC link

voltage at the nominal dc link voltage

22 Operation Mode Of Dynamic Voltage

Restorer

Generally the DVR is categorized into three-

operation modes which are injection mode stand-

by mode and protection mode (Nguyen and Saha

2004) The DVR goes into injection mode as soon

as power quality problem is detected In this

mode the three single phase ac voltages are

injected with compensating voltages in series with

required magnitude phase and waveform for

proper compensation In standby mode (normal

steady state condition) the DVR may either go

into short circuit operation or inject small voltage

to compensate the voltage drop on transformer

reactance or losses If over current on the load side

exceeds a permissible limit due to short circuit on

the load or large in-rush current the DVR will

switch to protection mode by being isolated from

the system using the by-pass switch which

removes the DVR from the system by supplying

another path of current

23 DVR Topology

Different topologies of DVR are discussed below

1 Energy System Topology

During a voltage sag the DVR injects voltages

and thereby restores the supply voltages In this

phase the DVR exchanges active and reactive

power with the surrounding system If active

power is supplied to the load by the DVR it needs

a source for the energy Two concepts are here

considered one concept uses stored energy and

the other concept uses no significant energy

storage

2 Compensation Techniques

There are three compensation strategies that are

normally used for sag compensation (Choi et al

2005) and (Wang and Choi 2008) They are the

pre-sag compensation in-phase compensation

and the minimum energy injection compensation

technique In pre-sag compensation the DVR

compensates for both the magnitude and angle

while for in-phase compensation compensation

for voltage magnitude only is required and no

phase compensation is required The minimum

energy injection compensation depends on

maximizing the active power supplied by the

network or keeping the apparent power constant

while decreasing the network reactive power

3 Sag Detection Techniques

A voltage sag detection technique detects the

occurrence of the sag the start point the end

point sag depth (magnitude to be restored) and

phase shift Common voltage sag detection

techniques are the peak value method root mean

square (rms) method Fourier Transform (FT)

method and the space vector method (Fitzer et al

2004) and (Bae et al 2010)

i Peak Value Method

The simplest method of monitoring the supply is

to monitor the peak or amplitude of the supply

voltage then comparing it with a reference A

controller could be set to recognize if there is a

difference greater than a specified value (10)

and switch in the inverter

ii Root Mean Square (rms) Method

The start time of the sag can be defined as the first

point of Vrms when drops below 09 pu To find

the end time of the sag search for an interval

where Vrms drops below 09 pu for at least half a

cycle The recovery time is then chosen as the first

point in this interval

iii Fourier Transform (FT)

The FT is achieved through orthogonal

decomposition of power system signal Generally

trigonometrically orthogonal function set or

exponential orthogonal function set is utilized By

applying FT to each supply phase it is possible to

obtain the magnitude and phase of each of the



frequency components of the supply waveform

For practical digital implementation Windowed

Fast Fourier Transform (WFFT) is used which

can easily be implemented in real time control

system

iv Space Vector Method

The three phase voltages Vabc are transformed into

a two dimension voltage Vdq which in turn can be

transferred into magnitude and angle Any

deviation in any quantity reveals the occurrence of

an event Comparing these quantities with

reference ones will quantify the disturbance in the

dq-frame which had to be transformed back to the

abc frame This method has no time delay yet

requires complex controller

3 METHODOLOGY

31 Modeling

In order to understand and analyze the actual

behaviour and operation of Dynamic Voltage

Restorer a prototype of this DVR needs to be

modeled and simulated Therefore this section has

to do with the modeling and simulation of this

DVR in MATLABSimulinkSimPowerSystem

environment

The block diagram which shows the systemic

operation of DVR is shown in Fig 31

Fig 31 Block diagram of component units of DVR

32 Basic Principle of Operation of DVR

The DVR is connected in series between the

supply system and the load And this DVR is

mainly made up of seven basic units which are

Energy Storage Unit Inverter Unit Control

system Unit Filter Unit Series Injection

Transformer Unit Protection Unit and the DC

Charging Unit

The control system unit which has a

controller monitors and measures the magnitude

of the supply voltage and compares it with a

reference voltage which will subsequently control

and determine the range of operation of the DVR

So when there is a voltage drop or voltage rise

(as a result of voltage sag or voltage swell

respectively) in the supply system the controller

measures the voltage and compares it with a

reference voltage and consequently generates an

error signal (voltage difference) which will then

be used as a modulating signal to modulate the

carrier wave of the inverter using Pulse Width

Modulation (PWM) scheme This modulation of

the carrier wave signal of the inverter will then

determine the amount and kind (whether positive

or negative voltage for voltage sag or voltage

swell respectively) of voltage the inverter will

generate from the energy storage unit The

inverter actually generates the reactive power

needed by itself while it generates the active

power by DC-AC energy conversion from the

energy storage system Then the voltage is passed

Space

Vector

Analysis



through the shunt filter to eliminate the harmonic

generated by the inverter The filtered voltage is

injected in series and synchronism to the supply

system by the injection transformer The series

injected voltage will now be added to the supply

voltage to restore the proper or desired magnitude

of the load voltage

Calculation For DVR Voltage Value

Fig 32 Equivalent circuit diagram of DVR

The system impedance ZS as shown in Fig32

depends on the fault level of the load bus When

the system voltage (VSupply) drops the DVR injects

a series voltage VDVR through the injection

transformer so that the desired load voltage

magnitude VL can be maintained The series

injected voltage of the DVR can be written as

(31)

Vreference = Desired supply voltage

Desired Supply Voltage = Desired load voltage +

line drop

(32)

where Vsag = voltage sag

VL = Load voltage

ZS = System impedance

IL = Load current

Vsupply = Supply voltage

The load current IL is given by

(33)

where PL = Load real power

QL = Load reactive power

33 Modeling of Control System Unit

A control system is implemented in software for

control and protection of the DVR as shown in

Fig11 To detect voltage sag the voltage is

continuously measured and a Phase Locked Loop

(PLL) is implemented to detect the phase and

angular position of the three-phased supply

voltage

Fig33 Schematic of a typical PI controller

After measuring the supply voltage and

subsequent implementation of phase locked loop

space vector control will be applied to the DVR

hence the ABC voltages will be transformed in to

a space vector representation

(34)

The space vectors are transformed in to a

rotating d-q reference frame according to equation

below

(35)

A voltage sag is detected by measuring the

error between the dq-voltage of the supply and the

reference values

| |

radic( )

(36)

Load VL

ZDVR VDVR ZS

Vsupply

+

-

VIN

VR PI

CONTRO-

LLER

Output of

PI CONTRO-

LLER



The d-reference component is set to rated

voltage and the q-reference component is set to

zero

But ABC Voltages can be transformed

directly to d-q rotating reference frame as shown

below

(37)

Also d-q rotating reference frame can be

transformed to ABC as follows

(38)

Also ABC an d-q voltages can be converted

to positive sequence V1 negative sequenceV2

and zero sequence voltages as shown below

radic

(39)

where complex also

phase angle = frasl

The hardware model of control system is shown in

Fig34

Fig 34 Typical model of the control system unit

Models of other units that make up the DVR

The model of the inverter unit is as shown in Fig

35

dq0

sin_cos

abc

dq0_to_abcTransformation

abc

sin_cos

dq0

abc_to_dq0Transformation

Vabc_pu3

g A B C

+ -

Universal BridgeInverter

Vabc A

B

C

a

b

c

Three-PhaseV-I Measurement1

Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

Freq

Sin_Cos

wt

Discrete

Virtual PLL



Fig 35 Inverter model

Also the model for energy source unit is

shown in Fig 36 made up of battery and DC-

link

Fig 36 The energy source model

The model for the injection unit is shown in

Fig37

Fig 37 Injection transformer unit model

The model for filter unit is shown in Fig38 made

up of capacitor and inductor

34 A Complete MATLABSIMULINK

Model of DVR

The MATLABSimulink models of the

different components that make up the DVR are

assembled to form the complete set of DVR as

shown in Fig 39 Fig38 Filter unit model

g

A

B

C

+

-

Universal BridgeInverter1

A B C

Three-PhaseHarmonic Filter



4 SIMULATION RESULT AND

DISCUSSION

After modeling the simulation was done

using MATLABSimulinkSimPowerSystem

carried out on the hardware model of the Dynamic

Voltage Restorer Different operating conditions

on the respective cases were assumed as follows

1) when there is no faulty condition without

DVR

2) when there is short-circuit faulty condition

without DVR


with DVR

These case scenarios capture power quality

issues like voltage sag voltage swell and

harmonic problems

The output of the hardware simulations has to

do with the results of the different three phase

voltage magnitude waveforms and its positive

sequence magnitude all in per unit across the

load obtained from the simulation of modeled

DVR and its operations are presented according to

the various cases

CASE 1 When there is no faulty condition and

without DVR operation

Fig41 shows the resulting waveform of AC

supply that has no fault and without DVR

operation This indicate that a good quality AC

supply should be purely sinusoidal and should

maintain constant magnitude across the load as

shown

Fig 41 Voltage at load point without DVR and fault



CASE 2 When there is faulty condition of voltage sag and without DVR operation

Fig39 A Complete MATLABSimulinkSimPowerSystem Model of DVR

DiscreteTs = 5e-005 s

powergui

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu4

Vabc_pu3

Vabc_pu2

Vabc_pu1

Vabc_pu

g A B C

+ -


A1+

A1

B1+

B1

C1+

C1

A2+

A2

B2+

B2

C2+

C2

Three-Phase Transformer12 Terminals1

A

B

C

A

B

C

Three-Phase Fault

VabcA

B

C

a

b

c


VabcA

B

C

abc


VabcA

B

C

a

b

c


Vabc A

B

C

a

b

c


VabcA

B

C

a

b

c

Three-PhaseV-I Measurement

A

B

C

a

b

c

Three-PhaseTransformer

(Two Windings)1

A

B

C

a

b

c


(Two Windings)

A

B

C

Three-PhaseSeries RLC Load1

A

B

C

Three-PhaseSeries RLC Load

N

A

B

C

Three-PhaseProgrammable

Voltage Source1

A

B

C

Three-PhaseHarmonic Filter2

A B C


A

B

C

A

B

C

Source impedance

100 MVA

short circuit level

Series R Branch1

Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)4

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)2

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)1

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)

Freq

Sin_Cos

wt

Discrete

Virtual PLL

DC capacitor linkDC Voltage Source

Breaker2

Breaker1

Breaker

A

B

C

a

b

c

Three-Phase Breaker1



Fig42 Voltage at load point with sag and without DVR

In Fig42 the result of three-phase AC

voltage magnitude waveform under a faulty

condition of voltage sag (40 or 04 reduction)

which causes voltage drop at the time range of 02

-03s is shown And since there is absence of

DVR the voltage drop will not be compensated

for

CASE 3 When there is faulty condition of

voltage sag and with DVR in operation

Fig 43 Voltage response of the test system with sag and DVR

Fig43 shows the result of three-phase AC




-03s However with the presence of DVR it will

respond immediately to compensate the voltage

drop by injecting a positive voltage in series with

the line voltage to restore the load voltage to about

95-98 of its nominal value



CASE 4 When there is faulty condition of voltage

swell and without DVR operation

Fig44 Voltage at load point with swell and without DVR

The result shown in Fig44 is the three-phase

AC voltage magnitude waveform under a faulty

condition of voltage swell (40 or 04 increment)

which causes voltage rise at the time range of 02 -

03s And since there is absence of DVR the

voltage rise will not be compensated for


swell and with DVR in operation

Fig 45 Voltage response of test system with swell and DVR

Fig45 is the result of three-phase AC voltage

magnitude waveform under a faulty condition of

voltage swell (40 or 04 increment) which causes

voltage swell at the time range of 02 -03s And



since there is present of DVR it will react

immediately to compensate the voltage swell by

injecting a negative voltage in series with the line

voltage to restore the load voltage to about 95-98

of its nominal value

CASE 6 Non-linear load with DVR operation

The effect of filter in response to harmonic

distortion being introduced by non-linear loads is

shown in Fig46

Fig 46 Operation of DVR filter for mitigation of harmonic distortion

The first graph (B1) shows the distortion effect on

supply current by harmonics being generated by

non-linear load But in the presence of DVR

Filter it will filter out the harmonics and restore

the supply current back to its original sinusoidal

waveform as shown in second graph (B2)

5 CONCLUSION

Power Quality has been a key factor in the

power system transmission and distribution Power

quality problems such as voltage sag voltage swell

and harmonic distortion have had adverse effects

on industrial equipment power system structures

and economy at large Therefore in a quest to

mitigate these problems a custom power device

Dynamic Voltage Restorer (DVR) has been

proposed for the mitigation of these power quality

problems

Furthermore from the analysis of the results

obtained from the simulation of the modeled DVR

using MATLABSimulinkSimPowerSystem in

this paper DVR operates to restore the desired load

voltage magnitude to about 95-98 therefore it

has been proven satisfactory that DVR can be used

to provide acceptable solution to power quality

problems of voltage sag voltage swell and

harmonic distortion Also because of the fast

response small size and dynamism of this device

it is the most efficient and effective custom power

device for power quality improvement

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Bae B Jeong J Lee J and Han B (2010)

Novel Sag Detection Method for Line-

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Quality Improvement Using Dynamic

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Analysis and Solution of Power Quality



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Utilization 16(1) 15-25

Choi S Li J and Vilathgamuwa M (2005) A

Generalized Voltage Compensation

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El-Gamma M Abou-Ghazal AY amp El-

Shennawy TI (2011) Dynamic Voltage

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Fitzer C Barnes M and Green P (2004)

Voltage Sag Detection Technique for a

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Transaction on Industry Applications

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Ganesh S Reddy K and Ram B (2009) A

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Haque M H (2011) Compensation of

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Proceedings IEEE Porto 110-13

Haque M H (2001) Voltage Sag correction by

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power injection IEEE Power Engineering

Review 21(5) 56 ndash 58

IEEE Standard board IEEE Std 1159-1995 IEEE

Recommended Practice for Monitoring

Electric Power Quality The Institute of

Electrical and Electronics Engineers Inc

1995 11-23

Jena AK Mohapatra B amp Pradlon K (2012)

Modeling and Simulation of a Dynamic

Voltage Restorer Electrical Power

Quality and Utilization Journal 3 12-32

Kavitha M Chandrasekhar T amp Reddy D

(2013) Designing of dynamic Voltage

Restorer to Improve the Power Quality for

Restructured Power System American

Journal of Electrical Power and Energy

System 2(3) 94-97 2013 Available from

httpdoi1011648jepes2013020315

[Accessed 20th May 2014]

Lalitha V amp Vindhya K (2013) Improvement of

Power Quality Using Repetitive

Controller for Dynamic Voltage Restorer

International Journal of Science and

Research 2(11) 416-420

Li B H Choi SS and Vilathgamuwa DW

(2001) Design considerations on the line

side filter used in the Dynamic Voltage

Restorer IEE Proceedings of Generation

Transmission and Distribution 148(1) 1

ndash 7

Loh P Vilathgamuwa M Tang S amp Long H

(2004) Multilevel Dynamic Voltage

Restorer IEEE Power Electronics Letters

2(4) 125-130

Mallela V S Solanki P S amp Chaturvedi A

(2005) Role of a Dynamic Voltage

Restorer in Mitigation of Power Quality

Problems International Conference on

Communication Computer amp Power

161- 166

Nielsen J G (2002) Design and Control of

Dynamic Voltage Restorer A Dissertation

Submitted in partial fulfilment of the

Requirements of Aalborg University for

the Degree of Doctor of Philosophy

Aalborg Aalborg University Denmark

Nguyen PT amp Saha T K (2004) Dynamic

Voltage Restorer against balanced and

unbalanced voltage sags Modeling and

simulation IEEE transactions on Power

Delivery 4(5) 1-6

Pandey A (2013) Dynamic Voltage Restorer and

its application at LV and MV level

International Journal of Scientific and

Engineering Research 4 668-671

Pante N and Kristina L (2008) Factor Affecting

Characteristic of Voltage Sag Due to Fault

in Power System Journal of Electrical

Engineering 5 (1) 171-182

Reddy K amp Anyaneyulu K S (2001) A New

Technique for improving The Power

Quality In Power Transformer By FPGA

Journal of Theoretical and Applied

Information Technology 169 -175

Roncero-Saacutenchez P Acha E Ortega-Calderon

Vicente Feliu J E amp Garciacutea-Cerrada A

(2009) A versatile control scheme for a



dynamic voltage restorer for power-

quality improvement IEEE Transactiwon


Tumay M Teke A Bayindir K amp Cuma M

(2011) Simulation And Modeling of a


Transaction on Power Delivery 20(1)

20-25

Vivek M and Srividhya P (2013) Power Quality

Improvement Techniques In Hybrid

System International Journal of

Technology And Engineering Research

[Online] 3(5) 56-59 Available from

httpwwwijatercom

Wang Q and Choi S (2008) An Energy-Saving

Series Compensation Strategy Subject to

Injected Voltage and Input-Power Limits


23(2) 1121-1131



DVR are the compensation for voltage sag

voltage swell and harmonic distortion Earlier

power quality improvement started on the

generation and transmission system where

Flexible AC Transmission System (FACTS)

devices were used which include STATCOM ndash

Static Synchronous Compensator SSSC ndash Static

Synchronous Series Compensator IPFC ndash

Interline Power Flow Controller UPFC ndash Unified

Power Flow Controller (Pandey 2013) But these

FACTS devices were for transmission system

only However in the distribution system today

it is a major focus for power quality improvement

and also due to the disadvantages attached to

FACTS devices such as fixed compensation

bulkiness and electromagnetic interference These

urged the power system and power electronic

engineers to think of developing an adjustable and

dynamic solution and led to the modification of

the FACTS devices for use in the distribution

system so that power quality can be further

improved These modified devices are called

Custom Power Devices which include Distributed

Static Compensators (DSTATCOM) Dynamic

Voltage Restorer (DVR) Uninterruptable Power

Supply (UPS) Static Var Compensator (SVC)

Among these devices DVR is the most effective

and efficient custom power device because of its

low cost smaller size fast response towards the

disturbance and most importantly its dynamism

makes it possible to inject only the quantity or

amount of voltage required at a particular time

(Nielsen 2002)

The DVR is still a modern device which

insertion and use in the grid system is still rare

(El-Gamma et al 2011) DVR was treated in

(Nguyen and Saha 2004) and (Jena et al 2012)

where the analysis was based on voltage sag

mitigation only They did not provide solution for

protection against other power quality problems

like voltage swell harmonic distortion Also the

work in (Tumay et al 2011) dealt with DVR for

rectifying the problem of voltage sag only as they

considered voltage sag to be the most severe since

sensitive loads are very susceptible to temporary

changes in voltage In the paper (Benachaiba and

Ferdi 2008a) DVR was designed for hharmonics

distortion compensation and in this work voltage

sag and swell were not treated or considered

Also in the work in (Lalitha and Vindhya 2013)

controller based on repetitive control for a DVR to

compensate voltage sag harmonic voltage and

voltage imbalance was discussed The research in

(Vivek and Srividhya 2013) was aimed at getting

good quality of power and minimizing the power

tariff achieved by implementing hybrid power

generation system but focused on the various

methods of power quality improvement

techniques in hybrid power system

However observation showed that most of

these aforementioned works provided limited

information about the comprehensive operation

and detailed description of the modelling design

control and simulation aspects

This paper analyses power quality and its

associated problems and subsequently presents a

concise comprehensive information on the

descriptive modeling simulation and operation of

DVR for the mitigation of voltage sag voltage

swell and harmonic distortion in the distribution

power system

11 POWER QUALITY AND ITS

PROBLEMS

Power Quality problems involve variation in

voltage magnitude variation in frequency and

variation in waveform shape (harmonics)

The problems of Power Quality can be categorized

as

ii Short-duration power quality disturbances ndash

which include voltage sag voltage swell and

voltage transient (impulsesurge)

iii Long-duration power quality disturbances ndash

which include overvoltage and undervoltage

iv Continuous and steady-state power quality

disturbance ndash which include harmonic

flickers and voltage imbalance (Benachaiba

and Fredi 2008b)



111 Voltage Sag
































and (Pandey 2013)

112 Voltage Swell










magnitude




















































DVR





Fig22











































Restorer




















23 DVR Topology











storage
























2004) and (Bae et al 2010)

i Peak Value Method



























system











3 METHODOLOGY

31 Modeling







environment











Charging Unit
























Space

Vector

Analysis









of the load voltage










(31)



line drop

(32)


VL = Load voltage


IL = Load current



(33)










voltage







(34)



below

(35)



reference values

| |

radic( )

(36)

Load VL

ZDVR VDVR ZS

Vsupply

+

-

VIN

VR PI

CONTRO-

LLER

Output of

PI CONTRO-

LLER





zero



below

(37)



(38)




radic

(39)

where complex also

phase angle = frasl


Fig34




35

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu3

g A B C

+ -


Vabc A

B

C

a

b

c


Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

Freq

Sin_Cos

wt

Discrete

Virtual PLL






link



Fig37





Model of DVR





g

A

B

C

+

-


A B C





DISCUSSION







DVR


without DVR


with DVR



harmonic problems







the various cases








shown







powergui

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu4

Vabc_pu3

Vabc_pu2

Vabc_pu1

Vabc_pu

g A B C

+ -


A1+

A1

B1+

B1

C1+

C1

A2+

A2

B2+

B2

C2+

C2


A

B

C

A

B

C

Three-Phase Fault

VabcA

B

C

a

b

c


VabcA

B

C

abc


VabcA

B

C

a

b

c


Vabc A

B

C

a

b

c


VabcA

B

C

a

b

c


A

B

C

a

b

c


(Two Windings)1

A

B

C

a

b

c


(Two Windings)

A

B

C


A

B

C


N

A

B

C


Voltage Source1

A

B

C


A B C


A

B

C

A

B

C

Source impedance

100 MVA

short circuit level

Series R Branch1

Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)4

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)2

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)1

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)

Freq

Sin_Cos

wt

Discrete

Virtual PLL


Breaker2

Breaker1

Breaker

A

B

C

a

b

c











for









































shown in Fig46








5 CONCLUSION










problems













REFERENCES




[Online] 10(13) 1-8





25(2) 1210-1211

























40(1) 203-212






208-214













1995 11-23

















Research 2(11) 416-420






ndash 7




2(4) 125-130






161- 166











Delivery 4(5) 1-6


























20-25






httpwwwijatercom





23(2) 1121-1131



111 Voltage Sag
































and (Pandey 2013)

112 Voltage Swell










magnitude




















































DVR





Fig22











































Restorer




















23 DVR Topology











storage
























2004) and (Bae et al 2010)

i Peak Value Method



























system











3 METHODOLOGY

31 Modeling







environment











Charging Unit
























Space

Vector

Analysis









of the load voltage










(31)



line drop

(32)


VL = Load voltage


IL = Load current



(33)










voltage







(34)



below

(35)



reference values

| |

radic( )

(36)

Load VL

ZDVR VDVR ZS

Vsupply

+

-

VIN

VR PI

CONTRO-

LLER

Output of

PI CONTRO-

LLER





zero



below

(37)



(38)




radic

(39)

where complex also

phase angle = frasl


Fig34




35

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu3

g A B C

+ -


Vabc A

B

C

a

b

c


Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

Freq

Sin_Cos

wt

Discrete

Virtual PLL






link



Fig37





Model of DVR





g

A

B

C

+

-


A B C





DISCUSSION







DVR


without DVR


with DVR



harmonic problems







the various cases








shown







powergui

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu4

Vabc_pu3

Vabc_pu2

Vabc_pu1

Vabc_pu

g A B C

+ -


A1+

A1

B1+

B1

C1+

C1

A2+

A2

B2+

B2

C2+

C2


A

B

C

A

B

C

Three-Phase Fault

VabcA

B

C

a

b

c


VabcA

B

C

abc


VabcA

B

C

a

b

c


Vabc A

B

C

a

b

c


VabcA

B

C

a

b

c


A

B

C

a

b

c


(Two Windings)1

A

B

C

a

b

c


(Two Windings)

A

B

C


A

B

C


N

A

B

C


Voltage Source1

A

B

C


A B C


A

B

C

A

B

C

Source impedance

100 MVA

short circuit level

Series R Branch1

Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)4

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)2

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)1

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)

Freq

Sin_Cos

wt

Discrete

Virtual PLL


Breaker2

Breaker1

Breaker

A

B

C

a

b

c











for









































shown in Fig46








5 CONCLUSION










problems













REFERENCES




[Online] 10(13) 1-8





25(2) 1210-1211

























40(1) 203-212






208-214













1995 11-23

















Research 2(11) 416-420






ndash 7




2(4) 125-130






161- 166











Delivery 4(5) 1-6


























20-25






httpwwwijatercom





23(2) 1121-1131




















































DVR





Fig22











































Restorer




















23 DVR Topology











storage
























2004) and (Bae et al 2010)

i Peak Value Method



























system











3 METHODOLOGY

31 Modeling







environment











Charging Unit
























Space

Vector

Analysis









of the load voltage










(31)



line drop

(32)


VL = Load voltage


IL = Load current



(33)










voltage







(34)



below

(35)



reference values

| |

radic( )

(36)

Load VL

ZDVR VDVR ZS

Vsupply

+

-

VIN

VR PI

CONTRO-

LLER

Output of

PI CONTRO-

LLER





zero



below

(37)



(38)




radic

(39)

where complex also

phase angle = frasl


Fig34




35

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu3

g A B C

+ -


Vabc A

B

C

a

b

c


Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

Freq

Sin_Cos

wt

Discrete

Virtual PLL






link



Fig37





Model of DVR





g

A

B

C

+

-


A B C





DISCUSSION







DVR


without DVR


with DVR



harmonic problems







the various cases








shown







powergui

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu4

Vabc_pu3

Vabc_pu2

Vabc_pu1

Vabc_pu

g A B C

+ -


A1+

A1

B1+

B1

C1+

C1

A2+

A2

B2+

B2

C2+

C2


A

B

C

A

B

C

Three-Phase Fault

VabcA

B

C

a

b

c


VabcA

B

C

abc


VabcA

B

C

a

b

c


Vabc A

B

C

a

b

c


VabcA

B

C

a

b

c


A

B

C

a

b

c


(Two Windings)1

A

B

C

a

b

c


(Two Windings)

A

B

C


A

B

C


N

A

B

C


Voltage Source1

A

B

C


A B C


A

B

C

A

B

C

Source impedance

100 MVA

short circuit level

Series R Branch1

Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)4

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)2

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)1

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)

Freq

Sin_Cos

wt

Discrete

Virtual PLL


Breaker2

Breaker1

Breaker

A

B

C

a

b

c











for









































shown in Fig46








5 CONCLUSION










problems













REFERENCES




[Online] 10(13) 1-8





25(2) 1210-1211

























40(1) 203-212






208-214













1995 11-23

















Research 2(11) 416-420






ndash 7




2(4) 125-130






161- 166











Delivery 4(5) 1-6


























20-25






httpwwwijatercom





23(2) 1121-1131





















Restorer




















23 DVR Topology











storage
























2004) and (Bae et al 2010)

i Peak Value Method



























system











3 METHODOLOGY

31 Modeling







environment











Charging Unit
























Space

Vector

Analysis









of the load voltage










(31)



line drop

(32)


VL = Load voltage


IL = Load current



(33)










voltage







(34)



below

(35)



reference values

| |

radic( )

(36)

Load VL

ZDVR VDVR ZS

Vsupply

+

-

VIN

VR PI

CONTRO-

LLER

Output of

PI CONTRO-

LLER





zero



below

(37)



(38)




radic

(39)

where complex also

phase angle = frasl


Fig34




35

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu3

g A B C

+ -


Vabc A

B

C

a

b

c


Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

Freq

Sin_Cos

wt

Discrete

Virtual PLL






link



Fig37





Model of DVR





g

A

B

C

+

-


A B C





DISCUSSION







DVR


without DVR


with DVR



harmonic problems







the various cases








shown







powergui

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu4

Vabc_pu3

Vabc_pu2

Vabc_pu1

Vabc_pu

g A B C

+ -


A1+

A1

B1+

B1

C1+

C1

A2+

A2

B2+

B2

C2+

C2


A

B

C

A

B

C

Three-Phase Fault

VabcA

B

C

a

b

c


VabcA

B

C

abc


VabcA

B

C

a

b

c


Vabc A

B

C

a

b

c


VabcA

B

C

a

b

c


A

B

C

a

b

c


(Two Windings)1

A

B

C

a

b

c


(Two Windings)

A

B

C


A

B

C


N

A

B

C


Voltage Source1

A

B

C


A B C


A

B

C

A

B

C

Source impedance

100 MVA

short circuit level

Series R Branch1

Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)4

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)2

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)1

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)

Freq

Sin_Cos

wt

Discrete

Virtual PLL


Breaker2

Breaker1

Breaker

A

B

C

a

b

c











for









































shown in Fig46








5 CONCLUSION










problems













REFERENCES




[Online] 10(13) 1-8





25(2) 1210-1211

























40(1) 203-212






208-214













1995 11-23

















Research 2(11) 416-420






ndash 7




2(4) 125-130






161- 166











Delivery 4(5) 1-6


























20-25






httpwwwijatercom





23(2) 1121-1131







system











3 METHODOLOGY

31 Modeling







environment











Charging Unit
























Space

Vector

Analysis









of the load voltage










(31)



line drop

(32)


VL = Load voltage


IL = Load current



(33)










voltage







(34)



below

(35)



reference values

| |

radic( )

(36)

Load VL

ZDVR VDVR ZS

Vsupply

+

-

VIN

VR PI

CONTRO-

LLER

Output of

PI CONTRO-

LLER





zero



below

(37)



(38)




radic

(39)

where complex also

phase angle = frasl


Fig34




35

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu3

g A B C

+ -


Vabc A

B

C

a

b

c


Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

Freq

Sin_Cos

wt

Discrete

Virtual PLL






link



Fig37





Model of DVR





g

A

B

C

+

-


A B C





DISCUSSION







DVR


without DVR


with DVR



harmonic problems







the various cases








shown







powergui

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu4

Vabc_pu3

Vabc_pu2

Vabc_pu1

Vabc_pu

g A B C

+ -


A1+

A1

B1+

B1

C1+

C1

A2+

A2

B2+

B2

C2+

C2


A

B

C

A

B

C

Three-Phase Fault

VabcA

B

C

a

b

c


VabcA

B

C

abc


VabcA

B

C

a

b

c


Vabc A

B

C

a

b

c


VabcA

B

C

a

b

c


A

B

C

a

b

c


(Two Windings)1

A

B

C

a

b

c


(Two Windings)

A

B

C


A

B

C


N

A

B

C


Voltage Source1

A

B

C


A B C


A

B

C

A

B

C

Source impedance

100 MVA

short circuit level

Series R Branch1

Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)4

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)2

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)1

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)

Freq

Sin_Cos

wt

Discrete

Virtual PLL


Breaker2

Breaker1

Breaker

A

B

C

a

b

c











for









































shown in Fig46








5 CONCLUSION










problems













REFERENCES




[Online] 10(13) 1-8





25(2) 1210-1211

























40(1) 203-212






208-214













1995 11-23

















Research 2(11) 416-420






ndash 7




2(4) 125-130






161- 166











Delivery 4(5) 1-6


























20-25






httpwwwijatercom





23(2) 1121-1131









of the load voltage










(31)



line drop

(32)


VL = Load voltage


IL = Load current



(33)










voltage







(34)



below

(35)



reference values

| |

radic( )

(36)

Load VL

ZDVR VDVR ZS

Vsupply

+

-

VIN

VR PI

CONTRO-

LLER

Output of

PI CONTRO-

LLER





zero



below

(37)



(38)




radic

(39)

where complex also

phase angle = frasl


Fig34




35

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu3

g A B C

+ -


Vabc A

B

C

a

b

c


Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

Freq

Sin_Cos

wt

Discrete

Virtual PLL






link



Fig37





Model of DVR





g

A

B

C

+

-


A B C





DISCUSSION







DVR


without DVR


with DVR



harmonic problems







the various cases








shown







powergui

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu4

Vabc_pu3

Vabc_pu2

Vabc_pu1

Vabc_pu

g A B C

+ -


A1+

A1

B1+

B1

C1+

C1

A2+

A2

B2+

B2

C2+

C2


A

B

C

A

B

C

Three-Phase Fault

VabcA

B

C

a

b

c


VabcA

B

C

abc


VabcA

B

C

a

b

c


Vabc A

B

C

a

b

c


VabcA

B

C

a

b

c


A

B

C

a

b

c


(Two Windings)1

A

B

C

a

b

c


(Two Windings)

A

B

C


A

B

C


N

A

B

C


Voltage Source1

A

B

C


A B C


A

B

C

A

B

C

Source impedance

100 MVA

short circuit level

Series R Branch1

Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)4

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)2

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)1

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)

Freq

Sin_Cos

wt

Discrete

Virtual PLL


Breaker2

Breaker1

Breaker

A

B

C

a

b

c











for









































shown in Fig46








5 CONCLUSION










problems













REFERENCES




[Online] 10(13) 1-8





25(2) 1210-1211

























40(1) 203-212






208-214













1995 11-23

















Research 2(11) 416-420






ndash 7




2(4) 125-130






161- 166











Delivery 4(5) 1-6


























20-25






httpwwwijatercom





23(2) 1121-1131





zero



below

(37)



(38)




radic

(39)

where complex also

phase angle = frasl


Fig34




35

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu3

g A B C

+ -


Vabc A

B

C

a

b

c


Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

Freq

Sin_Cos

wt

Discrete

Virtual PLL






link



Fig37





Model of DVR





g

A

B

C

+

-


A B C





DISCUSSION







DVR


without DVR


with DVR



harmonic problems







the various cases








shown







powergui

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu4

Vabc_pu3

Vabc_pu2

Vabc_pu1

Vabc_pu

g A B C

+ -


A1+

A1

B1+

B1

C1+

C1

A2+

A2

B2+

B2

C2+

C2


A

B

C

A

B

C

Three-Phase Fault

VabcA

B

C

a

b

c


VabcA

B

C

abc


VabcA

B

C

a

b

c


Vabc A

B

C

a

b

c


VabcA

B

C

a

b

c


A

B

C

a

b

c


(Two Windings)1

A

B

C

a

b

c


(Two Windings)

A

B

C


A

B

C


N

A

B

C


Voltage Source1

A

B

C


A B C


A

B

C

A

B

C

Source impedance

100 MVA

short circuit level

Series R Branch1

Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)4

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)2

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)1

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)

Freq

Sin_Cos

wt

Discrete

Virtual PLL


Breaker2

Breaker1

Breaker

A

B

C

a

b

c











for









































shown in Fig46








5 CONCLUSION










problems













REFERENCES




[Online] 10(13) 1-8





25(2) 1210-1211

























40(1) 203-212






208-214













1995 11-23

















Research 2(11) 416-420






ndash 7




2(4) 125-130






161- 166











Delivery 4(5) 1-6


























20-25






httpwwwijatercom





23(2) 1121-1131






link



Fig37





Model of DVR





g

A

B

C

+

-


A B C





DISCUSSION







DVR


without DVR


with DVR



harmonic problems







the various cases








shown







powergui

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu4

Vabc_pu3

Vabc_pu2

Vabc_pu1

Vabc_pu

g A B C

+ -


A1+

A1

B1+

B1

C1+

C1

A2+

A2

B2+

B2

C2+

C2


A

B

C

A

B

C

Three-Phase Fault

VabcA

B

C

a

b

c


VabcA

B

C

abc


VabcA

B

C

a

b

c


Vabc A

B

C

a

b

c


VabcA

B

C

a

b

c


A

B

C

a

b

c


(Two Windings)1

A

B

C

a

b

c


(Two Windings)

A

B

C


A

B

C


N

A

B

C


Voltage Source1

A

B

C


A B C


A

B

C

A

B

C

Source impedance

100 MVA

short circuit level

Series R Branch1

Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)4

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)2

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)1

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)

Freq

Sin_Cos

wt

Discrete

Virtual PLL


Breaker2

Breaker1

Breaker

A

B

C

a

b

c











for









































shown in Fig46








5 CONCLUSION










problems













REFERENCES




[Online] 10(13) 1-8





25(2) 1210-1211

























40(1) 203-212






208-214













1995 11-23

















Research 2(11) 416-420






ndash 7




2(4) 125-130






161- 166











Delivery 4(5) 1-6


























20-25






httpwwwijatercom





23(2) 1121-1131




DISCUSSION







DVR


without DVR


with DVR



harmonic problems







the various cases








shown







powergui

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu4

Vabc_pu3

Vabc_pu2

Vabc_pu1

Vabc_pu

g A B C

+ -


A1+

A1

B1+

B1

C1+

C1

A2+

A2

B2+

B2

C2+

C2


A

B

C

A

B

C

Three-Phase Fault

VabcA

B

C

a

b

c


VabcA

B

C

abc


VabcA

B

C

a

b

c


Vabc A

B

C

a

b

c


VabcA

B

C

a

b

c


A

B

C

a

b

c


(Two Windings)1

A

B

C

a

b

c


(Two Windings)

A

B

C


A

B

C


N

A

B

C


Voltage Source1

A

B

C


A B C


A

B

C

A

B

C

Source impedance

100 MVA

short circuit level

Series R Branch1

Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)4

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)2

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)1

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)

Freq

Sin_Cos

wt

Discrete

Virtual PLL


Breaker2

Breaker1

Breaker

A

B

C

a

b

c











for









































shown in Fig46








5 CONCLUSION










problems













REFERENCES




[Online] 10(13) 1-8





25(2) 1210-1211

























40(1) 203-212






208-214













1995 11-23

















Research 2(11) 416-420






ndash 7




2(4) 125-130






161- 166











Delivery 4(5) 1-6


























20-25






httpwwwijatercom





23(2) 1121-1131






powergui

dq0

sin_cos

abc


abc

sin_cos

dq0


Vabc_pu4

Vabc_pu3

Vabc_pu2

Vabc_pu1

Vabc_pu

g A B C

+ -


A1+

A1

B1+

B1

C1+

C1

A2+

A2

B2+

B2

C2+

C2


A

B

C

A

B

C

Three-Phase Fault

VabcA

B

C

a

b

c


VabcA

B

C

abc


VabcA

B

C

a

b

c


Vabc A

B

C

a

b

c


VabcA

B

C

a

b

c


A

B

C

a

b

c


(Two Windings)1

A

B

C

a

b

c


(Two Windings)

A

B

C


A

B

C


N

A

B

C


Voltage Source1

A

B

C


A B C


A

B

C

A

B

C

Source impedance

100 MVA

short circuit level

Series R Branch1

Scope3

Scope

415Reference

Voltage

Signal(s) Pulses

PWM Generator

PID(s)

PID Controller

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)4

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)3

abc

Mag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)2

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)1

abcMag

Phase

Discrete 3-phase

Sequence Analyzer

(Fundamental)

Freq

Sin_Cos

wt

Discrete

Virtual PLL


Breaker2

Breaker1

Breaker

A

B

C

a

b

c











for









































shown in Fig46








5 CONCLUSION










problems













REFERENCES




[Online] 10(13) 1-8





25(2) 1210-1211

























40(1) 203-212






208-214













1995 11-23

















Research 2(11) 416-420






ndash 7




2(4) 125-130






161- 166











Delivery 4(5) 1-6


























20-25






httpwwwijatercom





23(2) 1121-1131










for









































shown in Fig46








5 CONCLUSION










problems













REFERENCES




[Online] 10(13) 1-8





25(2) 1210-1211

























40(1) 203-212






208-214













1995 11-23

















Research 2(11) 416-420






ndash 7




2(4) 125-130






161- 166











Delivery 4(5) 1-6


























20-25






httpwwwijatercom





23(2) 1121-1131





























shown in Fig46








5 CONCLUSION










problems













REFERENCES




[Online] 10(13) 1-8





25(2) 1210-1211

























40(1) 203-212






208-214













1995 11-23

















Research 2(11) 416-420






ndash 7




2(4) 125-130






161- 166











Delivery 4(5) 1-6


























20-25






httpwwwijatercom





23(2) 1121-1131



















40(1) 203-212






208-214













1995 11-23

















Research 2(11) 416-420






ndash 7




2(4) 125-130






161- 166











Delivery 4(5) 1-6


























20-25






httpwwwijatercom





23(2) 1121-1131










20-25






httpwwwijatercom





23(2) 1121-1131

MODELING AND SIMULATION OF DYNAMIC VOLTAGE RESTORER · PDF fileMODELING AND SIMULATION OF...

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