Type test Notes

8/10/2019 Type test Notes

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Automation Products Laboratories

TYPE TESTING OF PROTECTION RELAYS

Automation Products Laboratories - St Leonards Avenue Stafford ST17 4LX EnglandTel: +44 (0)1785 223251 Fax: +44 (0)1785 212232ALSTOM GRID UK LTD. Registered Office : St Leonards Avenue Stafford ST17 4LXRegistered in England : 4955841

1. INTRODUCTION TO TYPE TESTING OF PROTECTIVE,

AUXILIARY & TRIPPING RELAYS.

A relay or protective scheme may only be called upon to operate once or twice in its

entire life. It must however be accurate and reliable. It must be completely stable

against maloperation when subjected to any of the numerous onerous conditions

that may occur in its normal working environment.

Since the prime function of a protective relay is to operate correctly under abnormal

or extreme conditions, it is essential that the relays be tested under those conditions.

Abnormal conditions may be caused by a number of reasons. These can be

summarised into the following categories:

Overvoltages or overcurrent.

Interfering noise.

Problems with the DC or AC auxiliary supply.

Mechanical vibration.

Extreme environmental conditions, temperature, humidity.

Transients caused by Voltage or Current Transformers.

Transients caused by large transformers, or HV cables and lines when energised.

It is also important to determine the accuracy or response of the relay within the

specified operating range. The relay itself must not be a source of interference to

other equipment, and although it is connected to the primary system, it must pose no

safety hazard to personnel or plant.


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5/4/2012 2 Typetest_notes_2012.doc

It is therefore necessary to carry out TYPE TESTING on newly developed relays to

assess their performance. Type testing is quite different from ROUTINE

PRODUCTION relay functional testing which is carried out on every relay before it

leaves the factory.

The International Electrotechnical Vocabularydefines type tests as:

A test of one or more devices made to a certain design,

to show that the design meets certain specifications.

Before a product is developed the required performance is specified, as are the

required performance tests, and before any tests are carried out, test plans and test

procedures are written and agreed. At ALSTOM Grid, Stafford, the Automation

Products Laboratories carries out the EMC, Environmental, Electrical and Safety

Type Testing. The functional Type Testing is carried out by the R&D Department in

China (CTC) although Automation Products Laboratories will review both the

Functional Test Specifications and the Functional Test Results.

As a parallel process to this, the Automation Products Laboratories are also

responsible for gaining third party approval for the relays. The electricity suppliers

have their own formal approval processes for protection relays and the Automation

Products Laboratories take the responsibility of ensuring that the relays conform to

these requirements and that the approval process is carried out correctly. In the UK

the Energy Networks Association (ENA) is the main approval body which represents

a group of relay users involved in the generation, transmission, distribution and

supply of electricity. Its membership consists of mostly UK companies, although

there are associate members from Ireland, Japan, South Africa and Finland.

The market for protection relays is worldwide, and, it is most important that

internationally agreed standards are used as the basis for the tests carried out.

Hence most references in the publications are to IEC standards (International

Electrotechnical Commission).


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So, what type tests are carried out? Broadly speaking they can be split into five

groups.

1. Functional Tests

2. Electrical Tests

3. Environmental Tests

4. EMC Tests

5. Safety Tests

Functional tests are carried out to determine the accuracy and repeatability of each

of the discrete functions that the product can perform. They also determine the

effect of the interaction between each of the discrete functions within the relay, and

also the interaction between other items of equipment that the relay may be

interfaced with.

The electrical tests are designed to test that the relay is not damaged by transient

overvoltages that may be experienced on site. In addition the affect of variations on

the relays auxiliary supply voltage are also determined.

Environmental tests are designed to ensure that relays can operate as expected inthe environment they are installed in. Power system protection relays can be

installed anywhere in the world, in a diversity of environments. In order to ensure

reliability in operation, and whether they are fit for purpose, they are subjected to the

most stringent type tests, as specified in the IEC standards.

EMC tests are designed to ensure that the protective relay is not affected or capable

of affecting other equipment that is located within the substation. Compliance with

the EMC directive is a legal requirement of all products sold within Europe.

Safety tests and reviews are designed to ensure that the product being sold is safe

ensuring that it causes no injury to users during its normal operation. Compliance

with the Low Voltage Directive (LVD) is a legal requirement of all products sold within

Europe and along with the EMC Directive is essential for CE marking the product. In

addition Underwriters Laboratories (UL) and Atmosphres Explosibles (ATEX)

testing is carried out in conjunction with the appropriate authorities.


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1.1 UKAS ACCREDITATION

The Automation Products Laboratories are accredited by the United Kingdom

Accreditation Services (UKAS). The laboratory complies and operates to ISO/IEC

17025 requirements to provide a quality service. The Schedule of Accreditation

detailing the tests for which Automation Products Laboratories is accredited is shown

on the UKAS web site; www.UKAS.org.

All equipment used to carry out the tests, is calibrated by an accredited test house

which includes our own Electrical Measurements Laboratory which is also UKAS

accredited.

Specialised tests are performed at external accredited test houses, these being:

Mechanical testing: Vibration response and endurance, shock response and

withstand, bump and seismic.

Enclosure protection testing: dust and water ingress

Electromagnetic Interference testing: Conducted and radiated emissions, conducted

and radiated immunity.

2. FUNCTIONAL TESTS

2.1 ACCURACY AND REPEATABILITY OF PROTECTION FUNCTIONS

Taken to the basic definition, functional tests consist of applying voltage, current or

frequency variations over the complete setting range for the function under test, and

measuring the performance in terms of accuracy and repeatability.

They are carried out under reference laboratory conditions, usually in a temperature

and humidity controlled environment.


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Consider the following simple overcurrent element.

Element Range Step Size

I>1 0.08 - 4.00In 0.01In

I>2 0.08 - 32In 0.01In

Directionality Forward/Reverse/Non-directional

RCA -95to +95 1

Characteristic DT/IDMT

Definite Time Delay 0 - 100s 0.01s

IEC IDMT Time Delay IEC Standard Inverse

IEC Very Inverse

IEC Extremely Inverse

UK Long Time Inverse

Time Multiplier Setting

(TMS)

0.025 - 1.2 0.025

IEEE IDMT Time Delay IEEE Moderately Inverse

IEEE Very Inverse

IEEE Extremely Inverse

US-C08 Inverse

US-C02 Short Time Inverse

Time Dial (TD) 0.5 15 0.1

IEC Reset Time (DT only) 0 - 100s 0.01s

IEEE Reset Time IDMT/DT

IEEE DT Reset Time 0 - 100s 0.01s

IEEE IDMT Reset Time IEEE Moderately Inverse

IEEE Very Inverse

IEEE Extremely Inverse

US-C08 Inverse

US-C02 Short Time Inverse


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The functions described above are the basic building blocks of any overcurrent relay,

and, the following tests would be carried out to prove the functionality:

Test 1:- Three phase non-directional pick up and drop off accuracy over complete

current setting range for both stages

Test 2:- Three phase directional pick up and drop off accuracy over complete

RCA setting range in the forward direction, current angle sweep


RCA setting range in the reverse direction, current angle sweep


RCA setting range in the forward direction, voltage angle sweep


RCA setting range in the reverse direction, voltage angle sweep

Test 6:- Three phase polarising voltage threshold test

Test 7:- Accuracy of DT timer over complete setting range

Test 8:- Accuracy of IDMT curves over claimed accuracy range

Test 9:- Accuracy of IDMT TMS/TD

Test 10:- Effect of changing fault current on IDMT operating times

Test 11:-Minimum Pick-Up of Starts and Trips for IDMT curves

Test 12:- Accuracy of reset timers

Test 13:- Effect of any blocking signals, opto inputs, VTS, Autoreclose

Test 14:- Voltage polarisation memory


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So, for even the most basic function, there are numerous tests that are carried out in

order to prove the correct implementation and operation of the function. This is a

very time consuming process, and for a large project, involves numerous engineers

and technicians for several months. In the case of the Px4x development, if only oneperson were to carry out all the test duties, it would take a total of 4 years to write the

test specifications, and 30 years to carry out all of the tests. Then there would be the

small matter of writing the type test reports!

2.2 RATINGS/BURDENS AND THERMAL WITHSTAND TESTS

In the case of measuring the burden and rating of the relays CTs, VTs, auxiliary

power supply and opto inputs, as well as the maximum quantities that these

components can withstand thermally, tests are performed to the requirementsdefined in:

IEC 60255-1 Electrical Relays Measuring Relays and Protection Equipment

Part 1: (Common Requirements)

This standard specifies the general performance requirements of all electrical

measuring relays and protection equipment used in the electrotechnical fields

covered by the IEC, and gives recommended values for ratings, burdens, markings

and accuracy claims.

In the case of the burden, this is measured for the CTs, VTs, opto inputs and

auxiliary voltage input. This involves measuring the operating voltage and/or current

drawn by each of these components over the specified operating range.

For ratings, this is again measured for the CTs, VTs, opto inputs and auxiliary

voltage input. This involves applying the appropriate input quantity at increasing

values for decreasing amounts of time. For CTs and VTs, thermocouples are

embedded in the windings and the temperature rise when the current or voltage is

applied is measured. This gives an indication of the point where the insulation is

about to melt or deteriorate, although the wire itself may be able to withstand the

applied quantity. This also determines the short time thermal withstand of the

components. For CTs this is the maximum current they will withstand for 1s, and for

VTs it is the maximum voltage they will withstand for 10s.


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Output contact ratings tests are performed to determine the ability of the relays

output contacts to perform repeated loaded operations. These are usually off the

shelf components, and the performance when breaking DC inductive and resistive

loads is rarely claimed by the manufacturer, so tests have to be performed todetermine this.

2.3 COMMUNICATIONS TESTS

More and more, relays are being developed with highly complex communication

capabilities to allow information exchange within intelligent protection schemes.

Tests are performed to ensure that various communication commands sent to the

relay result in the correct response. Tests are also performed to ensure that the

communications do not have an adverse effect on the protection performance of therelay, for example, increasing the operating time should a system fault occur whilst

the relay is communicating remotely with the control room.

2.4 MEASUREMENT PERFORMANCE

Modern relays have an extensive array of measured quantities, ranging from voltage,

current and frequency, active, reactive and apparent power, peak, fixed and rolling

demand values, and the sum of the broken current value used for circuit breaker

condition monitoring. The accuracy of these measured quantities has to bedetermined.

Some measurements are made directly by the relay, for example phase current and

voltage magnitude. However, others are derived by the relay, for example negative

sequence quantities, so tests have to be performed to determine the comparative

performance between direct and derived measurements.

2.5 INFLUENCING QUANTITIES

Along with measuring the accuracy and repeatability of each of the protection

functions, there is a whole suite of functional tests designed to determine the effect

of various parameters on the protection performance. These are known as

influencing quantities, and consist of the following.


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System X/R, where tests are performed with faults at various X/R values, ranging

from 1 up to 120. This results in fault waveforms with DC offset components, and

allows the effect on the relays operating times to be determined.

Point on Wave, where tests are performed with faults applied over the complete

point on wave range. Again this allows the affect on the relay operating times to

be determined.

Harmonics, where the effect of harmonics up to 17th, usually at 10% of the

fundamental are determined. Relays installed in proximity to HVDC links,

capacitive compensators, and arc furnaces will encounter distortion of the current

and voltage waveform due to the presence of various harmonics.

Frequency. Under normal operating conditions, the system frequency varies over

strictly specified limits. However, generator and motor protection relays are

required to operate over an extremely wide frequency range, and the accuracy

has to be determined over this range. Similarly, modern relays are dual

frequency rated to work with either 50Hz or 60Hz systems, so a comparison in the

protection performance at these two frequencies has to be determined. In fact, in

some cases, the functional tests are performed at 60Hz, because this is the most

onerous condition for the relay in terms of samples per cycle, i.e. the digital signal

processor (DSP) has to work 20% faster when the relay is configured for 60Hz,than it does for comparable performance at 50Hz.

Auxiliary Voltage. In modern relays, the operating range of the auxiliary voltage is

very wide, and therefore tests are performed to ensure that the relay will perform

its functions with the same accuracy and speed over the complete operating

voltage range. Most relay power supplies are also dual rated to work with either

AC or DC voltage, and a comparison in functional performance is made between

these two parameters.

2.6 CONJUNCTIVE TESTS

These tests derive their name from the fact that they are performed with a relay in

conjunction with a real current transformer, and realistic power system parameters.

The main aim of these tests is to determine:


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line current transformer requirements

realistic operating times

limits of stability for through faults

Traditionally, these tests have been performed on a bulky heavy current plant known

as the synthetic test plant, which used CTs, VTs, resistors and inductors to simulate

the line. This equipment has now been replaced with the RTDS (Real Time Digital

Simulator), which is essentially a power system simulator. (There is a separate

presentation and notes on the RTDS).

3. ELECTRICAL WITHSTAND TESTSThese tests are performed on unenergised relays to prove that:

1. The insulation employed is able to withstand the likely overvoltages encountered

in service.

2. The creepage and clearance distance between two points is large enough to

withstand the likely overvoltages encountered in service.

3.1 DIELECTRIC WITHSTAND TESTS.

The test is designed to prove the rated insulation voltage as declared by the

manufacturer.

ALSTOM Grid, Stafford, perform this test as a type test, and also as a standard

routine production test on every relay produced.

The relevant standard is:

IEC 60255-27 Measuring Relays and Protection Equipment Part 27: ProductSafety Requirements.

The relevant test levels used by ALSTOM Grid, Stafford are:

2.0 kV rms 50/60Hz for 1 minute applied between all terminals to case earth, and

then between independent circuits


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1.5 kV rms 50/60Hz for 1 minute applied across dedicated normally open contacts

of tripping output relays

1.0 kV rms 50/60Hz for 1 minute applied across normally open contacts of

watchdog relays or changeover pairs:

The pass criteria are that no breakdown or flashover shall occur, and the relay shall

still perform its main functions within the claimed tolerance after the test.

3.2 IMPULSE TEST.

The purpose of this test is to prove the ability of the relay's insulation to withstand

without damage overvoltages of very high amplitude and short duration, for example,

those caused by lightning strikes. The test waveform is shown below:

Impulse Waveform (not to scale)

50%

5 kV

1.2 us 50 us

Rise time : 1.2 us

Fall Time : 50 us to 50 %

Peak amplitude : 5 kV

Pulse energy : 0.5 Joules

Figure 1 High Voltage Impulse Test Waveform

The impulse is applied to a de-energised relay as 3 positive and 3 negative impulses

applied at intervals of not less than 5 seconds between:

all circuits and the case earth

all independent circuits

the terminals of independent circuits except for normally open contacts


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IEC 60255-27 Measuring Relays and Protection Equipment Part 27: Product

Safety Requirements.

The relevant test level is:

5kV, 1.2/50s waveform, 0.5J

The pass criteria are that no breakdown or flashover shall occur, and the relay shall

still perform its main functions within the claimed tolerance after the test.

3.3 INSULATION RESISTANCE

The purpose of this test is to measure the insulation resistance of the relay. 500Vdc

is applied for 5s, and the current drawn measured.


IEC 60255-5 - Electrical Relays Part 5: Insulation Coordination for Measuring

Relays and Protection Equipment Requirements and Tests.


100M between all circuits and the case earth, all independent circuits and

across normally open contacts

The pass criteria are that the insulation resistance must be greater than 100M

between the circuits specified above.

4. ENVIRONMENTAL TESTS

As well as proving that the relay can carry out all the functions claimed to the

required accuracy over the claimed operating range, it also has to be ensured that

the relay is capable of performing these functions correctly in the environment it may

find itself in. This involves testing each new product to extremes of temperature,

humidity and vibration.


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4.1 TEMPERATURE TESTS

Temperature tests are performed to ensure that the relay can withstand extremes in

operating and storage temperatures, both hot and cold.

The relevant standards are:

IEC 60068-2-1 Environmental Testing Part 2-1: Tests Test A: Cold

IEC 60068-2-2 - Environmental Testing Part 2-2: Tests Test B: Dry Heat

The test conditions are:

Storage and Transit -25C to +70C

Operating -25C to +55C

For the storage and transit test, the relay is placed unenergised in a temperature

cabinet at -25C and held at this temperature for duration of 96 hours. After this time

has elapsed, the relay is removed from the cabinet and allowed to return to the

ambient temperature. It is then powered up, and tested to ensure that all the

functions still operate within the claimed tolerances. The same process is repeated

for the +70C temperature.

The criteria for acceptance are that after the temperature testing the relay should

carry out its main functions correctly, and that the results should be within the

claimed tolerance.

For the operating temperature test, the relay is placed energised in the temperature

cabinet, and subjected to the following temperatures:

-25C, 0C, +20C, +40C, +55C.

At each of these temperatures the relay is allowed to stabilise until it is at the same

temperature as the test level. It is then powered down and up again, and subjected

to tests to determine that the functions still operate within the claimed tolerances.


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The criteria for acceptance in this case is that the relay must power up correctly,

(particularly important at low temperatures), it must perform all its main functions

within the claimed tolerance, and the LCD should be legible, (again, this is important

at the low temperatures).

4.2 HUMIDITY TESTS

Closely related to the temperature test is the humidity test. This test is carried out to

ensure that the relay will withstand and operate correctly when subjected to high

humidity at a constant temperature over a prescribed period.


IEC 60068-2-78 Environmental Testing Part 2-78: Tests Test Cab: Damp

Heat, Steady State.


+40C 2C and 93% relative humidity.

Duration 56 days.

For these tests the relay is placed in a humidity cabinet, and energised with normal

in-service quantities for the complete duration of the test. In practical terms this

usually means energising the relay with currents and voltages such that it is 10%

from the threshold for operation.

Functional tests are performed on the relay at 21 and 56 days, whilst it is still in the

cabinet. These tests determine if the main functions of the relay perform within the

claimed tolerance. Throughout the duration of the test the relay is monitored to

ensure that no unwanted operations occur.

Once the relay is removed from the humidity cabinet, its insulation resistance is

measured to ensure that it has not deteriorated to below the claimed level. The relay

is then functionally tested again, and finally dismantled to check for signs of

component corrosion and growth.


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In this case, the criteria for acceptance is that for the 56 day duration no unwanted

operations shall occur including transient operation of indicating devices. After the

test the relays insulation resistance should not have significantly reduced, and it

should perform all of its main protection and communications functions within theclaimed tolerance. The relay should also suffer no significant corrosion or growth,

and photographs are usually taken of each PCB and the case as a record of this.

4.2.1 Cyclic temperature and humidity testing

In addition to the 56-day humidity tests is the cyclic temperature with humidity test.

This test is a short term test which physically temperature stresses the relay whilst

subjecting it to a high ambient humidity. The test does not replace the 56 day test

but is used for testing extension to ranges or minor modifications to prove that thedesign is unaffected.


IEC 60068-2-30 Environmental Testing Part 2-1: Tests Test Db: Damp heat,

cyclic (12h + 12h cycle).


+25C 3C and 95% relative humidity/ +55C 2C and 95% relative humidity.

24 hour cycle period conforming to profile shown below.


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Figure 2 Cyclic temperature and humidity profile

For these tests the relay is placed in a humidity cabinet, and energised with normal

in-service quantities for the complete duration of the tests. In practical terms this

usually means energising the relay with currents and voltages such that it is 10%

from the threshold for operation. Throughout the duration of the test the relay is

monitored to ensure that no unwanted operations occur.

Once the relay is removed from the humidity cabinet, its insulation resistance ismeasured to ensure that it has not deteriorated to below the claimed level. The relay

is then functionally tested again, and finally dismantled to check for signs of

component corrosion and growth.


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The criteria for acceptance is that no unwanted operations shall occur including

transient operation of indicating devices. After the test the relays insulation

resistance should not have significantly reduced, and it should perform all of its main

protection and communications functions within the claimed tolerance. The relayshould also suffer no significant corrosion or growth, and photographs are usually

taken of each PCB and the case as a record of this.

4.3 ENCLOSURE PROTECTION TESTS

The object of this test is to prove that the casing system of the relay is protected

against the ingress of dust, moisture, fingers, tools etc., depending upon the test

level specified.


IEC 60529 - Degrees of Protection Provided by Enclosures (IP Code)

For MiDOS cases, (MCGG, KCGG, KBCH), the relevant level for the case is IP50,

which means protected from the ingress of dust particles, denoted by the 5, and no

protection against the ingress of moisture, denoted by the 0. For the MiCOM relays,

(P*40, P*30, the relevant level is IP52, which means, protected against the ingress of

dust particles, denoted by the 5, and protected against the ingress of dripping water

at an angle of 15, denoted by the 2.

For the dust test, the relay is placed in a chamber containing 2kg of powder per

cubic metre of the chamber volume. The chamber is then sealed, and the dust

circulated violently for a period of 8 hours, after which time the relay looks like this:


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Figure 3 LFZR relay on completion of the dust tests.

The relay is then carefully dismantled and inspected to determine the degree of

ingress of dust. The criteria for acceptance is that dust may enter and accumulate

inside the case as long as it does not interfere with the normal operation of the relay.

An engineering judgment is made about this considering the fact that the dust

encountered in service may be conductive.

For the dripping water test, the relay is subjected to 2.5mins of dripping water at a

flow rate of 3mm/min with the relay inclined at an angle of 15 from the horizontal.

The pass criteria in this case is that if any water has entered, it shall not:

Be sufficient to interfere with the correct operation of the equipment or impair

safety.

Deposit on insulated parts where it could lead to tracking along the creepage

distances.

Reach live parts or windings not designed to operate when wet.

Accumulate near the cable end or enter the cable if any.


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4.4 MECHANICAL TESTS

These tests are carried out to simulate a number of mechanical conditions the

product may have to endure during its lifetime. They fall into three distinct

categories, each designed to simulate a different environment, and covered by a

different standard.

Vibration

Shock and Bump

Seismic

In all cases, these tests are performed at an external test house. The relays are

subjected to the tests in the three axes, front to back, side to side, and top to bottom.

The relays are subjected to the mechanical tests in both the normal in service

condition, that is with current and voltage applied so that the relay is 10% from the

threshold of operation, and also on the tripped condition, where current and voltage

is applied so that the relay is 10% above the threshold for operation.

4.4.1 Vibration Tests

Two types of vibration tests are carried out:

Vibration Response

Vibration Endurance

The vibration response test is carried out with the relay energised to ensure that it is

able to perform correctly when subjected to constant mechanical vibration caused by

rotating machines such as generators and motors and industrial plant such as

crushers and mills.

The vibration endurance is performed with the relay unenergised, and is an

accelerated life test to simulate the effect of long term vibration and also some forms

of transportation.


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IEC 60255-21-1 Electrical Relays Part 21: Vibration, Shock, Bump and

Seismic Tests on Measuring Relays and Protection Equipment Section One:

Vibration Tests (Sinusoidal)

The relevant test levels are:

Vibration Response Class 2, 1g, 10 - 150Hz, 1 sweep, energised.

Vibration Endurance Class 2, 2g, 10 - 150Hz, 20 sweeps, unenergised.

For the vibration response test, the pass criteria is that the equipment shall not

maloperate, and shall still perform its main functions within the claimed tolerance

after the test.

For the vibration endurance test, the pass criteria is that the equipment should not

suffer any mechanical damage, and should still perform its main functions within the

claimed tolerance after the test.

4.4.2 Shock and Bump Test

Three types of shock and bump tests are carried out:

Shock Response

Shock Withstand

Bump

The aim of these tests is to ensure that the equipment can withstand similar

conditions both in service and in transportation. Circuit breaker mounted relays can

be subjected to shocks when the breaker operates, panel mounted relays can

receive impact shocks caused by ladders and doors. Relays can also undergo

repeated bumps during transit.


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The shock and bump impulse waveform is shown below:

Figure 4 Shock and Bump Impulse Waveform

- - - - - nominal pulse.

limits of tolerance.

D Duration of nominal pulse.

A Peak acceleration of nominal pulse.

T1 minimum time during which the pulse shall be monitored for shocks and

bumps produced using a conventional shock and bump machine.

T2 minimum time during which the pulse shall be monitored for shocks and

bumps produced using a vibration generator.


IEC 60255-21-2 - Electrical Relays Part 21: Vibration, Shock, Bump and

Seismic Tests on Measuring Relays and Protection Equipment Section Two:

Shock and Bump Tests


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Shock Response, Class 2, 10g, 11ms, 3 pulses, energised

Shock Withstand, Class 1, 15g, 11ms, 3 pulses, unenergised

Bump, Class 1, 10g, 16ms, 1000 pulses, unenergised

For the shock response test, the pass criteria is that the equipment shall not

maloperate and shall still perform its main functions within the claimed tolerance

after the test.

For the shock withstand and bump tests, the pass criteria is that the equipment

should not suffer any mechanical damage, and should still perform its main functions

within the claimed tolerance after the test.

4.4.3 Seismic Tests

The third type of mechanical test that is carried out is the seismic test. This is

designed to prove that the relay can operate as intended during earthquakes. The

test consists of a single axis sinusoidal sweep.


IEC 60255-21-3 - Electrical Relays Part 21: Vibration, Shock, Bump and

Seismic Tests on Measuring Relays and Protection Equipment Section Three:

Seismic Tests


Class 2, 1 - 35Hz, 1 sweep, energised.


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The sweep parameters are:

Peak displacement below

the cross over frequency.

(mm).

Peak acceleration above

the cross over frequency

(gn).

Number of

sweep cycles

in each axis

x (horizontal) y (vertical) X (horizontal) y (vertical)

7.5 3.5 2.0 1.0 1

The criteria for acceptance is that the equipment shall not maloperate, and shall still

perform its main functions within the claimed tolerance after the test.

5. ELECTROMAGNETIC COMPATIBILITY TESTS

There are numerous tests that are carried out to determine the ability of relays to

withstand the electrical environment in which they are installed. The substation

environment is a very severe environment in terms of the electrical and

electromagnetic interference that can arise. There are many sources of interference

within a substation, some originating internally, others being conducted along the

overhead lines or cables into the substation from external disturbances. The most

common sources are:

Switching Operations

System Faults

Lightning Strikes

Conductor Flashover

Telecommunication Operations e.g. mobile phones

A whole suite of tests are performed to simulate these types of interference, and

they fall under the broad category known as EMC, or Electromagnetic Compatibility

tests.


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Broadly speaking, EMC can be defined as:

The ability of equipments to co-exist in the same electromagnetic environment.

It is not a new subject and has been tested for by the military ever since the advent

of electronic equipment. If there is no electromagnetic compatibility in the battlefield

then the results can be disastrous.

For example, in 1967 there was an incident that occurred aboard the US aircraft

carrier Forrestal whilst cruising off the coast of North Vietnam. All the planes on

board were loaded with two 1000lb bombs each, as well as air to ground and air to

air missiles, and were fully fuelled and ready for take-off. Somewhere on the deck,

attached to the wing of an aircraft, was an improperly mounted shielded cable

connector. As the radar swept around, radio frequency voltages were generated in

the cable, which ignited a missile that shot across the deck, struck the aircraft

opposite and blew its fuel tanks apart. Its two bombs fell on to the deck and

exploded. Fire spread below decks, and by the time it was extinguished, 134 men

were either dead or missing. Total damages were put at $72 million.

Early Antilock Braking Systems (ABS) on both aircraft and automobiles were

susceptible to EMI. Accidents occurred when the brakes functioned improperly

because EMI disrupted the ABS control systems.

The sirens of passing emergency vehicles caused some electric wheel chairs and

invalid buggies to operate. This problem caused several deaths when these chairs

and buggies moved into the path of oncoming traffic and not responding to the users

input.

More recently there have been some problems with the throttle jamming wide open

on some modern cars that use fly by wire technology to control the engines throttle.

This also has caused several deaths and although the true cause of this was never

discovered it is widely believed that it was due to an EMC problem in the cars

concerned. This shows that an EMC related issue can be difficult to find and hard to

prove as it leaves no physical evidence particularly within the electronic circuits that it

effects which is particularly the case for microprocessor circuitry.


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So, it is evident that EMC can cause real and serious problems, and does need to be

taken into account when designing electronic equipment. To achieve this, in addition

to designing for statutory compliance to the EMC and Low Voltage Directives, the

following range of tests are carried out during our products development process.

5.1 DC INTERRUPT

This is a test to determine the maximum length of time that the relay can withstand

an interruption in the auxiliary supply without de-energising e.g. switching off, and

that time when it is exceeded and it does transiently switch off, that no maloperation

occurs.

It simulates the effect of a loose fuse in the battery circuit, or a short circuit in the

common DC supply, interrupted by a fuse. Another source of DC interruption is if

there is a power system fault and the battery is supplying both the relay and the

circuit breaker trip coils. When the battery energises the coils to initiate the circuit

breaker trip, the voltage may fall below the required level for operation of the relay

and hence a DC interrupt occurs.

The relevant test standard is:

IEC 60255-11 Measuring Relays and Protection Equipment Part 11: Voltage

Dips, Short Interruptions, Variations and Ripple on Auxiliary Power Supply Port.


20ms interruption without de-energising

10, 20, 30, 50, 100, 200, 300, 500, 1000 & 5000ms interruptions without

maloperating.

The relay is powered from a battery supply, and both short circuit and open circuit

interruptions are carried out. Each interruption is applied 10 times, and for auxiliary

power supplies with a large operating range, the tests are performed at minimum,

maximum, and other voltages across this range, to ensure compliance over the

complete range.


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The pass criteria for this test is that for interruptions of 20ms and less, the relay shall

not maloperate or de-energise, i.e. it shall not respond to the d.c. interrupt. For

interruptions greater than 20ms, the relay shall not maloperate, and power up

correctly.

5.2 AC RIPPLE ON DC SUPPLY

This test determines that the relay is able to operate correctly with a superimposed

AC voltage on the DC supply. This is caused by the station battery being charged by

the battery charger and the relevant waveform is shown below.

0.00

10.00

20.00

30.00

40.00

50.00

60.00

188

175

262

349

436

523

610

697

784

871

958

1045

1132

1219

1306

1393

Time (ms)

Voltage

Figure 5 AC ripple superimposed on DC supply


IEC 60255-11 Measuring Relays and Protection Equipment Part 11: Voltage

Dips, Short Interruptions, Variations and Ripple on Auxiliary Power Supply Port.


12% ripple peak to peak on the dc auxiliary voltage.


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For auxiliary power supplies with a large operating range, the tests are performed at

minimum, maximum, and other voltages across this range, to ensure compliance for

the complete range. The interference is applied using a full wave rectifier network,

connected in parallel with the battery supply.

The pass criteria is that during application of the ripple, the relay shall not

maloperate, and shall still perform its main functions within the claimed tolerance.

5.3 DC RAMP DOWN / RAMP UP

This test simulates a failed station battery charger, which would result in the auxiliary

voltage to the relay slowly ramping down. The ramp up part simulates the battery

being recharged after discharging. The relay must power up cleanly when the

voltage is applied and not maloperate.


ALSTOM Grid Staffords Standard, (no international or national standard exists)


1min/cycle and 100min/cycle where 1 cycle is Vmax - 0 - Vmax.

The pass criteria is that the relay must not maloperate by either issuing a trip

command or by chattering (rapidly switching off and on) when the boundary level of

the voltage is reached, for both the ramp down and ramp up test.

5.4 AC DIPS AND INTERRUPTIONS

This test is to evaluate the effects of a relay when subjected to voltage dips, short

interruptions and voltage variations.

The tests simulate the effect of a loose fuse or wire in the supply circuit, or a shortcircuit in the common AC supply. Another source of AC interruption is when a power

system fault or overload occurs. When loads are switched onto the supply, the

voltage may fall below the required level for operation of the relay and hence an AC

dip, interruption or variation may occur.



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IEC 61000-4-11 Electromagnetic Compatibility (EMC) Part 4-11: Testing and

Measurement Techniques - Voltage dips, Short Interruptions and Voltage

Variations Immunity Tests.


Minimum operating voltage 80% of lower voltage range (LVR)

Maximum operating voltage 110% of higher voltage range (HVR)

Voltage Dips and Interruptions:

0% i.e. 100% Voltage dip for a duration of: 10, 20, 50, 100, 200ms & 5s



Note: The above interruptions are applied for both positive and negative polarities

at the following angles: 0, 45, 90, 135, 180, 225, 270 and 315.

Voltage Variations: Levels of 100, 40 and 0% of the 80% of lower voltage range

(LVR) and 110% of higher voltage range (HVR) for 1s duration. Time to reach

new level: 2s.

An interruption of the supply shall not exceed 1 minute

Repetitive Start Tests to simulate a loose fuse

The tests are carried out using an AC voltage variation generator which powers the

relay, the tests are performed at 80% LVR AND 110% HVR with minimum, half and

full loading i.e. number of outputs etc energised.

The pass criteria for the above tests is for the specified variations and interruptions,

loss of function is permitted, but the relay must self recover with no loss or corruption

of settings or data and without operator intervention.


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5.5 HIGH FREQUENCY DISTURBANCE TEST

This test simulates the types of interference caused by switching operations and

power system faults, which cause high voltage transients. The high frequency

disturbance test waveform has a frequency of 100kHz, 1MHz, 3MHz, 10MHz or

30MHz. A typical 1MHz waveform is shown below.

Figure 6 1MHz High Frequency Disturbance Waveform

This type of interference is most likely to occur when a circuit breaker breaks load or

fault current, or an isolator/disconnector breaks load or charging current. This type

of voltage disturbance occurs for switching operations in any electrical circuit and the

frequency of oscillation is given by the equation below:

fLC

=1

2

Where:

F is the oscillating frequency

L is the inductance in the circuit

C is the capacitance in the circuit


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5.6 FAST TRANSIENT

This test simulates the type of high voltage interference caused by high-speed

disconnector operations in GIS substations, and by breakdown of the SF6 insulation

between the conductors and the earthed enclosure. Both these types of interference

can be inductively coupled onto the circuits connected to the relay, or be directly

introduced via the CT and VT inputs.

The fast transient waveform/pulse train is shown below.

5 ns rise time, 50 ns pulse width.

Repetition Period.

Burst Duration (15 ms)

Burst Period, 300 ms

V

V

t

t

Figure 7 Fast Transient Waveform/Pulse Train.

This waveform has a very fast rise time of around 5ns and duration above 50% of

the crest value of around 50ns.


IEC 60255-22-4 Measuring Relays and Protection Equipment Part 22-4:

Electrical Disturbance Tests Electrical Fast Transient/Burst Immunity Test.

Also ANSI/IEEE C37-90.1 - IEEE Standard for Surge Withstand Capabilities(SWC) Tests for Relays and Relay Systems Associated with Electrical Power

Apparatus.


Class III, 2kV, 5kHz, common mode only.


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Class IV, 4kV, 2.5kHz, common mode only.

ANSI/IEEE 4kV, 2.5kHz, common and differential mode.

The test is to one circuit at a time, and the test duration is 1min. Tests are carried

out on each circuit, with the relay in the following modes of operation:

1. Current and voltage applied at 90% of setting, (relay not tripped)

2. Current and voltage applied at 110% of setting, (relay tripped)

3. Main protection and communications functions are tested to determine the effect

of the interference.

The pass criteria is that during application of the fast transient, the relay shall not


5.7 POWER FREQUENCY INTERFERENCE

This test simulates the type of interference that is caused when there is a power

system fault and very high levels of fault current flow in the primary conductors or the

earth grid. This causes 50 or 60Hz interference to be induced onto control and

communications circuits.


IEC 60255-22-7 Electrical Relays Part 22-7: Electrical Disturbance Tests for

Measuring Relays and Protection Equipment Power Frequency Immunity Tests.


300Vrms common mode, 150V rms differential mode, applied to circuits for which

power system inputs are not connected.

Tests are carried out on each circuit, with the relay in the following modes of

operation:




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of the interference.

The pass criteria is that during application of the power frequency interference, the

relay shall not maloperate, and shall still perform its main functions within the

claimed tolerance.

5.8 ELECTROSTATIC DISCHARGE

This test simulates the type of high voltage interference that occurs when an

operator touches the relays front panel after being charged to a high potential by the

friction between dissimilar materials moving against one another.

For example, in 2005 Frank Clewer of Warrnambool in Western Victoria, Australia

attended a job interview wearing a nylon jacket and woollen shirt. As he walked

through the building he left scorch marks across the carpet which subsequently

ignited and led to everyone being evacuated. Firemen attending the scene cut the

power supply believing the fire had been caused by a power surge. However, they

later discovered that Mr Clewers clothes were carrying an electrical charge of 40kV!

In this case the discharge is only ever applied to the front panel of the relay, with the

cover both on and off. Two types of discharges are applied, air discharge and

contact discharge. Air discharges are used on surfaces that are normally insulators,

and contact discharges are used on surfaces that are normally conducting. Typical

application points are shown in the diagrams below.


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Figure 8 Application points for the ESD tests. Front cover on.

Figure 9 Application points for the ESD tests. Front cover removed.

The shaded labels indicate those points which are not normally conducting and

which will therefore be subjected to the air discharge. The unshaded areas are

those that are normally conducting and will be subjected to the contact discharge.


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IEC 60255-22-2 - Measuring Relays and Protection Equipment Part 22-2:

Electrical Disturbance Tests Electrostatic Discharge Tests


Cover On: Class 4, 8kV contact discharge, 15kV air discharge

Cover Off: Class 3, 6kV contact discharge, 8kV air discharge

In both cases above, all the lower test levels are also tested.

The discharge current waveform is as shown below:

Time, ns

Cu

rrent,%o

fPeak

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90

Rise Time = 0.7 to 1.0 ns.Current Specified for 30 ns and 60 ns

Figure 10 ESD Current Waveform

The test is performed with single discharges repeated on each test point 10 times

with positive polarity and 10 times with negative polarity at each test level, the timeinterval between successive discharges is greater than 1 second.

Tests are carried out at each level, with the relay in the following modes of operation:




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of the discharge.

The pass criteria is that during application of the electrostatic discharge, the relay

shall not maloperate, and shall still perform its main functions within the claimed

tolerance.

5.9 SURGE IMMUNITY

This test simulates interference caused by major power system disturbances such as

capacitor bank switching and lightning strikes on overhead lines within 5km of the

substation.

The open circuit voltage is a 1.2 /50s test waveshape, and the short circuit current

is a 8/20s waveshape. The short circuit output current can be as high as 2kA and

this test is therefore much more powerful and potentially destructive than any of the

other interference tests.



Electrical Disturbance Tests Surge Immunity Test.


Level 4, 4kV common mode, 2kV differential mode

The pass criteria is that during application of the surge, the relay shall not


Also, it shall not suffer any damage.

5.10 CONDUCTED AND RADIATED EMISSIONS

These tests arise primarily from the essential protection requirements of the

European Community (EU) directive on EMC which require manufacturers to ensure

that any equipment to be sold in the EU must not interfere with other equipment. To

achieve this it is necessary to measure the emissions from the equipment and

ensure that they are below the specified limits.


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Conducted emissions are measured from the equipments power supply ports and

communications ports.

Radiated emissions measurements are to ensure that the interference radiated from

the equipment is not at a level which could cause interference to other equipment.

When performing these two tests, the relay is in a quiescent condition, that is not

tripped, with currents and voltages applied at 90% of the setting values. This is

because for the majority of its life, the relay will be in the quiescent state and the

emission of electromagnetic interference when the relay is tripped is considered to

be of no significance.

The relevant test standards are:

IEC 60255-25 - Electrical Relays Part 25: Electromagnetic Emission Tests for

Measuring Relays and Protection Equipment

IEC 60255-26 Measuring Relays and Protection Equipment: Part 26:

Electromagnetic compatibility requirements

The relevant test levels are detailed in tables 1 to 4 below:

Table 1. Test level requirements for radiated emissions up to 1GHz

Frequency Range (MHz) Limits of Radiated Emissions at 10m1

Measurement Distance

Quasi-Peak dB (V/m)

30 to 230MHz 402

230 to 1000MHz 47

Notes:

1. The limits can be changed for different measurement distances

2. The lower limit shall apply at the transition frequency


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Table 2. Test level requirements for radiated emissions over 1GHz

Frequency Range (GHz) Limits of Radiated Emissions at 3m

Measurement Distance

Average Limit dB

(V/m)

Peak Limit dB (V/m)

1 to 3 561 76

3 to 6 60 80

Notes:


The highest frequency that the radiated emissions is measured up to is determined

by the highest frequency generated or used within the EUT as follows:

If the highest frequency of the internal sources of the EUT is less than108MHz, the measurement shall only be made up to 1GHz

If the highest frequency of the internal sources of the EUT is between108MHz and 500MHz, the measurement shall be made up to 2GHz

If the highest frequency of the internal sources of the EUT is between500MHz and 1GHz, the measurement shall be made up to 5GHz

If the highest frequency of the internal sources of the EUT is above1GHz, the measurement shall be made up to 5 times the highestfrequency or 6GHz, whichever is less

Table 3. Test level requirements for conducted emissions on power supply inputs

Frequency Range (MHz) Limits dB (V)

Quasi-peak Average

0.15 to 0.5 791 66

1

0.5 to 30 73 60

Notes:



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Table 4. Test level requirements for conducted emissions on communications ports

Frequency Range

(MHz)

Voltage limits1

dB (V)

Current limits1

dB (A)

Quasi-

peak

Average Quasi-peak Average

0.15 to 0.5 97 to 872 84 to 74

2 53 to 43

2 40 to 30

2

0.5 to 30 87 74 43 30

Notes:

1. The current and voltage disturbance limits are derived for use with animpedance stabilization network (ISN) which represents a common mode(asymmetric mode) impedance of 150to the communications port undertest (conversion factor is 20 log10150/1 = 44dB). The choice of whether thecurrent limits or voltage limits are used for measurement depends on theavailability of test equipment at the time of testing.

2. The limits decrease linearly with the logarithm of the frequency in the rangeof 0.15MHz to 0.5MHz

5.11 CONDUCTED AND RADIATED IMMUNITY

These tests are designed to ensure that the equipment is immune to levels ofinterference which it may be subjected to. The two tests conducted and radiated,

arise from the fact that for a conductor to be an efficient antenna, it must have a

length of at least wavelength of the electromagnetic wave it is required to conduct.

If a relay were to be subjected to radiated interference at 150kHz, then a conductor

of at least =300,000,000/150,000*4 = 500m long would be needed to conduct the

interference. Even with all the cabling attached and with the longest PCB track

length taken into account, it would be highly unlikely that the relay would be able to

conduct radiation of this frequency, and the test therefore, would have no effect.The interference has to be physically introduced by conduction, hence the conducted

immunity test.


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Note that at the radiated immunity lower frequency limit of 80MHz, a conductor

length of approximately 1.0m is required. At this frequency radiated immunity tests

can be performed in confidence that the relay will conduct this interference, through

a combination of the attached cabling and the PCB tracks.

Although the test standards state that all 6 faces of the equipment should be

subjected to the interference, in practice this is not carried out. Applying interference

to sides and top and bottom of the relay would have little affect as the circuitry inside

is effectively screened by the earthed metal case. However, the front and rear of the

relay are not completely enclosed by metal and are therefore not at all well screened,

and can be regarded as an EMC hole. Electromagnetic interference when directed

at the front and back of the relay can enter freely onto the PCBs inside.

When performing these two tests, the relay is in a quiescent condition, that is not

tripped, with currents and voltages applied at 90% of the setting values. This is

because for the majority of its life, the relay will be in the quiescent state and the

coincidence of an electromagnetic disturbance and a fault is considered to be

unlikely.

However, spot functional checks are performed at selected frequencies, where the

relay is tested to exercise all of its main protection and control functions, to ensure

that it will operate as expected, should it be required to do so.

The frequencies for the spot checks are in general selected to coincide with the radio

frequency broadcast bands and in particular, the frequencies of substation

attendants mobile communications. This is to ensure that when working in the

vicinity of a relay, the substation attendant should be able to operate his walkie-talkie

without fear of causing the relay to maloperate.

In addition, two further frequency sweeps are performed between 800MHz - 960MHz

and 1.4GHz - 2.0GHz at 30V/m to replicate the digital radio telephone and base

station frequencies used throughout the world.

The relevant test standards for the radiated immunity test are:


Electrical Disturbance Tests Radiated Electromagnetic Field Immunity.


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IEC 61000-4-3 Electromagnetic Compatibility (EMC. Testing and Measurement

Techniques. Radiated, Radio-Frequency, Electromagnetic Field Immunity Test

ANSI/IEEE C37.90.2 IEEE Standard for Withstand Capability of Relay Systems

to Radiated Electromagnetic Interference from Transceivers

The relevant test levels for these radiated immunity tests are:

Class III, 10V/m, 80MHz 2.7GHz with 80% AM modulation using a 1kHz

sinewave. Plus additional spot frequency tests at 80, 160, 380, 450, 900, 1850 &

2150MHz.

Digital Radio Telephone Sweep Tests,

Level 4, 30V/m, 800MHz - 960MHz

Level 4, 30V/m, 1.4GHz - 2.0GHz

Both with 80% AM modulation using a 1kHz sinewave

ANSI/IEEE, 35V/m 80MHz 1GHz with 80% AM modulation using a 1kHz

sinewave. Plus additional spot frequency tests at 80, 160, 450 and 900MHz.

The relevant test standard for the conducted immunity test is:

IEC 60255-22-6 Electrical Relays Part 22-6: Electrical Disturbance Tests for

Measuring Relays and Protection Equipment - Immunity to Conducted

Disturbances Induced by Radio Frequency Fields.

The relevant test level for the conducted immunity test is:

Class III, 10Vrms, 150kHz - 80MHz.

The pass criteria is that during application of the interference, the relay shall not



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5.12 POWER FREQUENCY MAGNETIC FIELD

These tests are designed to ensure that the equipment is immune to levels of

magnetic interference which it may be subjected to. The three tests (steady state,

pulsed and damped oscillatory magnetic field) arise from the fact that for different

site conditions the level and waveshape is altered.

5.12.1 Steady state magnetic field

These tests simulate the magnetic field that would be experienced by a device

located within close proximity of the power system. The relay is tested by immersing

the product within a magnetic field generated by two induction coils. The relay is

rotated such that in each axis it is subjected to the full magnetic field strength. The

test setup is represented in the diagram below.

EUTInduction Coil

Ground Plane

Induction Coil

Figure 11 Power frequency magnetic field set-up


IEC 61000-4-8 Electromagnetic Compatibility (EMC) Part 4-8: Testing and

Measurement Techniques Power Frequency Magnetic Field Immunity Test


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Level 5: 100A/m continuous and 1000A/m short duration

The pass criteria is that during the application of the steady state condition, the relay

shall not maloperate, and shall still perform its main functions within the claimed

tolerance. During the application of the short duration test, the main protection

function shall be exercised and verified that the operating characteristics of the relay

are unaffected.

5.12.2 Pulsed magnetic field


located within close proximity of the power system during a transient fault condition.

The generator for the induction coils shall produce a 6.4/16s waveshape with the

equipment configured as per the steady state magnetic field test.


IEC 61000-4-9 - Electromagnetic Compatibility (EMC) Part 4-9: Testing and

Measurement Techniques Pulse Magnetic Field Immunity Test.


Level 5: 1000A/m

The pass criteria is that during the application of the magnetic field, the relay shall

not maloperate, and shall still perform its main functions within the claimed tolerance.

5.12.3 Damped oscillatory magnetic field


located within close proximity of the power system during a transient fault condition.

The generator for the coil shall produce an oscillatory waveshape with a frequency of

100kHz and 1MHz, the equipment shall be configured as per steady state magnetic

field test.



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IEC 61000-4-10 - Electromagnetic Compatibility (EMC) Part 4-10: Testing and

Measurement Techniques Damped Oscillatory Magnetic Field Immunity.


Level 5: 100A/m, 100kHz and 1MHz

The pass criteria is that during the application of the magnetic field, the relay shall

not maloperate, and shall still perform its main functions within the claimed tolerance.

5.13 SAFETY

All relays sold within Europe are required to comply with the European Low Voltage

directive (LVD) 2006/95/EC. This requirement has been mandatory since January1997 in order to CE mark a product. Products manufactured before this date

complied with the appropriate Health and Safety at Work and Consumer Protection

legislation. Note that this legislation covers the Product Safety i.e. whether the

product is inherently safe and does not pose any hazard to the user of the product.

The ability to detect and protect against external events which might cause a hazard

is dealt with under any applicable functional safety requirements.

The essential requirement of the legislation is to show due diligence that the product

is safe and will not cause electric shock or f ire hazard under normal conditions and in

the presence of a single fault. The LVD requirements cover all aspects of the

product and are not just confined to the electrical connections. The product must be

well constructed according to good engineering practice i.e. it must not fall apart

exposing live parts or presenting mechanical hazards. Walls must not be so flimsy

that pressing against these reduces the insulation distances below the minimum

requirement. The product must be adequately insulated and be suitably earthed with

clearly labelled manufacturer mark/logo, product ratings and any safety warnings. In

addition the product publication must contain adequate instructions and warnings

affecting safety.

Compliance with the Low Voltage Directive is demonstrated via self assessment with

the information being stored in a Technical File.


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The key relevant test standards are:

IEC 60255-27 Measuring relays and protection equipment. Part 27: Product safety

Requirements.

IEC 60664-1 - Insulation Coordination for Equipment Within Low Voltage Systems

Part 1: Principles, requirements and tests

UL 508 edition 17, Industrial Control Equipment

UL 840 edition 3, Insulation Coordination Including Clearances and Creepage

Distances for Electrical Equipment.

IEC 60079-0, Electrical Apparatus for explosive gas atmospheres

and other BS, EN, IEC and UL standards referenced directly or indirectly by the

above documents.

6. ADDITIONAL TESTING

In addition to the Type Testing that is carried out on our products the Automation

Products Laboratories has introduced additional testing. This testing is carried out

after the Type Testing has been completed and prior to the products being available

for sale to our customers. This testing is carried out by a team of Technicians who

are effectively acting as our first customers. The testing focuses on the functional

operation of the product in that tests are carried out to ensure that the product

performs according to the claims made in the publications, the commissioning

instructions are also followed to ensure that they are correct and the product

performs as detailed in these instructions.

Another aspect of this additional testing is what we term Break-It Testing. This

again is carried out by our team of Technicians who carry out unusual tests on the

products to ensure that they do not have any unforeseen problems, an example of

such a test is:


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When downloading a settings file to a relay the communications cable is

disconnected before the file has downloaded, the relay will be tested to see

what effect this has had. The expected result is that the relay should

disregard the new settings and continue to operate using the original settingsand the relay shall continue to work and trip as expected.

There are many other examples of this type of testing that is carried out as Break-It

Testing but they are far too numerous to detail here. As can be seen from the above

example the intention is to carry out testing that is not usually part of routine Type

Testing and is more representative to how the product will be used in service.

The purpose of carrying out this additional and Break-It Testing is to ensure and if

necessary improve product quality and to detect and rectify any potential problems

with the products before they go on sale to our customers.

7. IEC 61850 CONFORMANCE TESTING.

7.1 OBJECTIVE

The objective as quoted in the UCAIug (Utilities Communication Architecture

International Users Group) Conformance Test Procedures for Server Devices is:

Does the protocol implementation of the DUT, conform to the IEC 61850 standard

and the PICS, MICS, PIXIT and ICD specifications as configured with SCD?

From the quotation above what is the:

DUT? The DUT is the Device Under Test.

IEC 61850 standard? The set of rules that the DUT protocol implementation

must adhere to. The standard is broken down into many parts of which the

following IEC documents for Communication networks and systems insubstations are used as reference during Conformance Testing:


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IEC 61850 Title

Part 1 Introduction and overview

Part 2 Glossary

Part 3 General Requirements

Part 4 System and Project Management

Part 5 Communication Requirements for Functions and Device Models

Part 6 Substation Automation System Configuration Language

Part 7-1 Basic Communication for Substation and Feeder Equipment - Principles and

Models

Part 7-2 Basic Communication for Substation and Feeder Equipment - Abstract

Communication Service Interface (ACSI)

Part 7-3 Basic Communication for Substation and Feeder Equipment Common Data

Classes and Attributes

Part 7-4 Basic Communication for Substation and Feeder Equipment - Compatible

Logical Node and Data Object Addressing

Part 8-1 Specific Communication Service Mapping (SCSM) Mapping to MMS

Part 10 Conformance Testing

PICS Protocol Implementation Conformance Statement, a document

supplied with the DUT outlining what protocol services from part 7-2 are

supported.

MICS Model Implementation Conformance Statement, a document supplied

with the DUT outlining what Logical Device, Node, Common Data Class and

Attribute Definitions from parts 7-3 and 7-4 are supported and the format they

will use in the DUT. The MICS will conform to what is available in the ICD

file.


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EQUIPMENT SIMULATOR

Ethernet switchin Hub

SIMULATOR / PC

ANALYZERDevice Under

Test DUT

Time Master

PIXIT Protocol Implementation eXtra Information for Testing, a document

supplied with the DUT outlining conditions considered for each Conformance

Block supported by the DUT. The Conformance Test Engineer will reference

this document throughout the testing as and when specified by the UCA TestProcedures to do so.

ICD IED Configuration Description, the empty configuration file/data model

for the DUT in SCL (Substation Configuration Description) format.

SCD Substation Configuration Description, the configured file/data model

for the DUT in SCL format.

7.2 TEST ENVIRONMENT

All tests are carried out by the Test Engineer in a laboratory faculty. Tests can be

performed to the UCA Test Procedures as Stafford Automation Product Laboratories

is a UCA Accredited Laboratory with ISO/IEC 17025 and ISO 9000 Quality System.

7.3 COMPONENTS IN THE TEST ENVIRONMENT

The test environment consists of the following components:


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7.4 TEST TOOLS

We are currently conducting tests using the latest versions of the globally used

KEMA tools. Although the diagram above specifies an external analyser and time

master, the PC will consist of all tools necessary to conduct the Conformance Test

including the analyser and time master. The test tools are:

UniCA Client Simulator KEMA Tool for running mandatory/conditional test

case as defined in the UCA Test Procedures.

UniCA Goose Simulator KEMA Tool for running mandatory/conditional

Goose Subscription test cases as defined in the UCA Test Procedures.

UniCA SCL Checker KEMA Tool for the checking of the SCL File and Data

Model to ensure that there are no conflicts when compared to what is defined

in the standard.

UniCA 61850 Analyser KEMA Tool allowing the Test Engineer to

interrogate and store trace files for all test cases.

Omicron Test Suite for Omicron CMC256plus Equipment Simulator for

generating input/output signals.

Time Master PC based software to time synchronise device/clients.

SCL Configuration Tool IEC 61850 IED Configurator, of the MiCOM S1

Studio Suite, used to configure device for test.

7.5 TESTING

We are currently running Conformance Tests to the latest edition of the UCA Test

Procedures, Conformance Test Procedures for Server Devices with IEC 61850-8-1

interface Revision 2.3.

UCA Test Procedures requires the testing of:

Documents

o PICS Protocol Implementation Conformance Statement


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o MICS Model Implementation Conformance Statement

o TICS Technical Issues Implementation Conformance Statement

o PIXIT Protocol Implementation eXtra Information for Testing

SCL Configuration Files/Data Model

o ICD IED Configuration Description

o SCD / CID Substation Configuration Description / Configured IED

Description

Test Cases for following Conformance Blocks if supported by the DUT:

o Basic Exchange Application Association and Server

o Data Set

o Substitution

o Setting Group

o Reporting Buffered, Unbuffered and Enhanced Buffered

o GOOSE - Publishing and Subscribing

o Control Direct Control, SBO Control (Select-Before-Operate), Enhanced

Direct Control and Enhanced SBO Control

o Time and Time Synchronization

o File Transfer

7.6 TESTING

When all tests have been performed and conducted according to the structured UCATest Procedures using the tools provided, an IEC 61850 Conformance Test

Certificate is issued.


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The tests and certificate can only be conducted and issued respectively by a UCA

accredited laboratory. Alstom Grid UK Stafford Laboratory is UCA accredited. A list

of other UCA accredited Test Laboratories from the UK and abroad is listed on the

UCA website, www.ucaiug.org.

References

[1] IEC 61850 Communication networks and systems in substations

[2] Conformance Test Procedures for Server Devices with IEC 61850-8-1 interface

Revision 2.3

[3] www.ucaiug.org

Type test Notes

Documents

Transcript of Type test Notes