Iec 60255 26 2013

IEC 60255 26 Edition 3 0 2013 05 INTERNATIONAL STANDARD NORME INTERNATIONALE Measuring relays and protection equipment – Part 26 Electromagnetic compatibility requirements Relais de mesure et disposit[.]

General

This section of the IEC 60255 series pertains to measuring relays and protection equipment, focusing on the integration of various devices to create power system protection schemes It also addresses the control, monitoring, communication, and process interface equipment associated with these systems.

This standard specifies the requirements for electromagnetic compatibility for measuring relays and protection equipment

Tests specified in this standard are not required for equipment not incorporating electronic circuits, for example electromechanical relays

The requirements specified in this standard are applicable to measuring relays and protection equipment in a new condition and all tests specified are type tests only.

Emission

This standard aims to establish limits and testing methods for measuring relays and protection equipment concerning electromagnetic emissions that could interfere with other devices.

The emission limits set for measuring relays and protection equipment in substations and power plants are crucial for ensuring electromagnetic compatibility These limits are designed to prevent disturbances from exceeding specified levels, thereby allowing other equipment to function properly.

Test requirements are specified for the enclosure and auxiliary power supply ports.

Immunity

This standard is to specify the immunity test requirements for measuring relays and protection equipment in relation to continuous and transient, conducted and radiated disturbances, including electrostatic discharges

The electromagnetic compatibility immunity requirements outlined are designed to guarantee sufficient immunity levels for measuring relays and protection equipment typically used in substations and power plants.

NOTE 1 Safety considerations are not covered in this standard

In certain situations, disturbance levels may surpass those outlined in this standard, particularly when using hand-held transmitters or mobile phones near measuring relays and protection equipment Therefore, it is essential to implement special precautions and procedures in these cases.

This document references essential documents that are crucial for its application For references with specific dates, only the cited edition is applicable In the case of undated references, the most recent edition of the referenced document, including any amendments, is relevant.

IEC 60255-1:2009, Measuring relays and protection equipment – Part 1: Common requirements

IEC 61000-4-2:2008, Electromagnetic compatibility (EMC) – Part 4-2: Testing and measurement techniques – Electrostatic discharge immunity test

IEC 61000-4-3:2006, Electromagnetic compatibility (EMC) – Part 4-3: Testing and measurement techniques – Radiated, radio-frequency, electromagnetic field immunity test

IEC 61000-4-4:2012, Electromagnetic compatibility (EMC) – Part 4-4: Testing and measurement techniques – Electrical fast transient/burst immunity test

IEC 61000-4-5:2005, Electromagnetic compatibility (EMC) – Part 4-5: Testing and measurement techniques – Surge immunity test

IEC 61000-4-6:2008, Electromagnetic compatibility (EMC) – Part 4-6: Testing and measurement techniques – Immunity to conducted disturbances, induced by radio-frequency fields

IEC 61000-4-8:2009, Electromagnetic compatibility (EMC) – Part 4-8: Testing and measurement techniques – Power frequency magnetic field immunity test

IEC 61000-4-11:2004, Electromagnetic compatibility (EMC) – Part 4-11: Testing and measurement techniques – Voltage dips, short interruptions and voltage variations immunity tests

IEC 61000-4-16:1998, Electromagnetic compatibility (EMC) – Part 4-16: Testing and measurement techniques – Test for immunity to conducted, common mode disturbances in the frequency range 0 Hz to 150 kHz

IEC 61000-4-17:1999, Electromagnetic compatibility (EMC) – Part 4-17: Testing and measurement techniques – Ripple on d.c input power port immunity test

IEC 61000-4-18:2006, Electromagnetic compatibility (EMC) – Part 4-18: Testing and measurement techniques – Damped oscillatory wave immunity test

IEC 61000-4-29:2000, Electromagnetic compatibility (EMC) – Part 4-29: Testing and measurement techniques – Voltage dips, short interruptions and voltage variations on d.c input power port immunity tests

CISPR 11:2009, Industrial, scientific and medical equipment – Radio-frequency disturbance characteristics – Limits and methods of measurement

CISPR 22:2008, Information technology equipment – Radio disturbance characteristics –

Limits and methods of measurement

For the purposes of this document, the following terms and definitions apply

EUT Equipment Under Test equipment which may be either a measuring relay or protection equipment

Small equipment, whether placed on a tabletop or standing on the floor, must fit within a cylindrical test volume measuring 1.2 meters in diameter and 1.5 meters in height above the ground plane, including its cables.

3.3 port particular interface of the specified EUT with the external electromagnetic environment

Communication port Output port Enclosure port

Figure 1 – Ports for measuring relays and protection equipment

3.4 auxiliary power supply port a.c or d.c auxiliary energizing input of the EUT

3.5 communication port interface with a communication and/or control system permanently connected to the EUT

3.6 enclosure port physical boundary of the EUT through which electromagnetic fields may radiate or impinge

3.7 functional earth port port on the EUT which is connected to earth for purposes other than electrical safety

3.8 input port port through which the EUT is energized or controlled in order to perform its function(s)

EXAMPLE Current and voltage transformer, binary input, etc

3.9 output port port through which the EUT produces predetermined changes

EXAMPLE Contacts, optocouplers, analogue output, etc

A CDN electrical circuit is designed to transfer energy between circuits while preventing test voltages applied to the Equipment Under Test (EUT) from impacting other devices, equipment, or systems that are not being tested.

CM mode between each active conductor and a specified reference, usually earth or ground reference plane

DM mode between any two of a specified set of active conductors

General

The environmental levels shall be selected in accordance with the most realistic installation and environmental conditions in which the EUT is expected to operate

Based on common installation practices, the recommended selection of test levels is the following:

Zone A, severe electrical environment

The installation is characterized by the following attributes:

• no suppression of electrical fast transients/bursts in the power supply and control and power circuits which are switched by relays and contactors;

• no separation of the industrial circuits from other circuits associated with environments of higher severity levels;

• no separation between power supply, control, signal and communication cables;

• use of common multi-core cables for control and signal lines

The outdoor environments of industrial process equipment, such as power stations, open-air high voltage substation switchyards, and gas-insulated switchgear, often lack standardized installation practices.

Zone B, typical electrical environment

The installation is characterized by the following attributes:

• no suppression of electrical fast transients/bursts in the power supply and control circuits which are switched by relays (no contactors);

• poor separation of the industrial circuits from other circuits associated with environments of higher severity levels;

• dedicated cables for power supply, control, signal and communication lines;

• poor separation between power supply, control, signal and communication cables;

• availability of earthing system represented by conductive pipes, ground conductors in the cable trays (connected to the protective earth system) and by a ground mesh

The area of industrial process equipment, the power plants and the relay room of open-air HV substations may be representative of this environment

Emission enclosure

Table 1 – Emission tests – Enclosure port

Item Environmental phenomena Frequency range Limits Basic standard Test procedure

40 dB(àV/m) quasi peak at 10 m

Measuring relays and protection equipment must meet class A limits, with peak levels reaching 80 dB(àV/m) at a distance of 3 meters Measurements can be taken at nominal distances of 3 m, 10 m, or 30 m, but distances under 10 m are permitted only for equipment that adheres to the specific definition outlined in section 3.2.

To ensure compliance, a normalization factor of 20 dB per decade will be applied to the measured data at a distance of 30 m Additionally, the specified limits for a 3 m separation distance are applicable solely to small equipment that meets the size criteria outlined in section 3.2.

• The highest internal source of an EUT is defined as the highest frequency generated or used within the EUT or on which the EUT operates or tunes

• If the highest frequency of the internal sources of the EUT is less than 108 MHz, the measurement shall only be made up to 1 GHz

• If the highest frequency of the internal sources of the EUT is between 108 MHz and

500 MHz, the measurement shall only be made up to 2 GHz

• If the highest frequency of the internal sources of the EUT is between 500 MHz and

1 GHz, the measurement shall only be made up to 5 GHz

For internal sources of the EUT with a highest frequency exceeding 1 GHz, measurements must be conducted up to either five times the highest frequency or 6 GHz, depending on which value is lower.

Emission auxiliary power supply port

Table 2 – Emission tests – Auxiliary power supply port

Item Environmental phenomena Frequency range Limits Basic standard Test procedure

2.1 Conducted emission 0,15 MHz to 0,50 MHz 79 dB(àV) quasi peak

CISPR 22 See 7.1.3 0,5 MHz to 30 MHz 73 dB(àV) quasi peak

Immunity enclosure

Table 3 – Immunity tests – Enclosure port

Item Environmental phenomena Test specification Units Basic standard Test procedure Acceptance criteria (see 8.2)

MHz MHz Test field strength

MHz MHz MHz MHz MHz MHz MHz Test field strength

Immunity auxiliary power supply port

Table 4 – Immunity tests – Auxiliary power supply port

4.1 Conducted disturbance induced by radio-frequency fields

Test frequency range 0,15 to 80 MHz

Test level (prior to modulation) 10 V (r.m.s.)

Rise time tr / duration time td

Differential mode 1 kV peak voltage

Common mode 2,5 kV peak voltage

Front time / time to half value 1,2 / 50 (8 / 20) às voltage (current)

4.8 Gradual shutdown/start-up (for d.c power supply)

- See 7.2.13 C a Manufacturer shall declare the duration among the following values: 0,5 cycle, 1 cycle, 2,5 cycles, 5 cycles,

10 cycles or 25 cycles b Manufacturer shall declare the duration among the following values: 10 ms, 20 ms, 30 ms, 50 ms, 100 ms,

200 ms, 300 ms, 500 ms or 1 000 ms c Test shall be done at a frequency of twice the specified power system frequency(s) d “10/12 cycles” means “10 cycles for 50 Hz test” and “12 cycles for 60 Hz test”.

Immunity communication port

Table 5 – Immunity tests – Communication port

Differential mode 0 kV peak voltage

Common mode 1 kV peak voltage

Front time / time to half value 1,2 / 50 (8 /

Coupling capacitor a 0 àF a These coupling values are for screened communication ports For unscreened communication ports use coupling values given in Table 6, item 6.4.

Immunity input and output ports

Table 6 – Immunity tests – Input and output ports

Differential mode c 1 kV peak voltage

Common mode 2,5 kV peak voltage

Front time / time to half value 1,2/50 (8/20) às voltage (current)

The 0.47 µF coupling capacitor is specifically designed for power frequency tests applicable only to binary input ports For screened input/output, such as transducer connections, refer to Table 5, item 5.4 for appropriate coupling methods In harsher environments, a differential test voltage of 2.5 kV may be necessary for current and voltage transformer inputs.

Immunity functional earth port

Table 7 – Immunity tests – Functional earth port

7 Test set-up and procedures

Emission

General

The tests shall be carried out with the equipment under reference conditions as stated in

Testing will be conducted using the rated values of auxiliary and input energizing quantities applied to the relevant circuits of the Equipment Under Test (EUT) These values must reflect typical quiescent conditions during normal operation, ensuring that the EUT is not in a transient or active state Additionally, half of the binary inputs and half of the output relays will be energized, and any communication modules present will be activated.

For relays with a wide operating power supply range or rating, the radiated emissions shall be performed on the lowest and the highest nominal voltage of the relay power supply

The conducted emission shall be performed on all nominal voltages of the relay power supply

Measuring relays and protection equipment typically remain in a quiescent state throughout their operational life, with only brief periods of activity During these short instances, the emissions from the equipment under test (EUT) are generally deemed insignificant.

Radiated emission

Test set-up Test procedure

Test configuration In accordance with CISPR 11 for radiated emission below 1 GHz and in accordance with CISPR 22 for radiated emission above 1 GHz

Distance and method See Table 1

Details of mounting Installed according to manufacturer’s specification

Acceptance criteria Class A limits See Table 1

Conducted emission

Test configuration In accordance with CISPR 22

Applicable ports A.C and d.c auxiliary power supply port

Details of mounting Installed according to manufacturer’s specification

Acceptance criteria Class A limits See Table 2

Immunity

General

The general test set-up, i.e the test generator, coupling and decoupling devices for each immunity test is specified in the appropriate basic standard for each test

7.2.2 details the general conditions that shall be complied with when carrying out immunity testing to measuring relays and protection equipment

7.2.3 to 7.2.13 detail the test procedures and specific applications of the immunity tests that shall be applied to measuring relays and protection equipment.

General test conditions

The test reference conditions must align with IEC 60255-1, unless the applicable basic standard from the IEC 61000-4 series specifies stricter tolerances for these conditions.

In cases where multiple identical circuits with numerous input or output ports, such as binary inputs or output contacts, are present on a board or module within the Equipment Under Test (EUT), it is sufficient to test only three circuits from each board or module in every slot to demonstrate compliance with the specific test.

This only applies to immunity tests that are applied to ports of the EUT rather than the enclosure as a whole

The EUT must be configured and set up according to the manufacturer's recommendations to accurately reflect its typical usage in normal service conditions.

Input and output ports shall be connected and energized as appropriate in line with normal service conditions and installation practice

The EUT communication port(s) shall be connected and configured in accordance with the manufacturer’s recommendations

NOTE Some guidance on testing is given in Annex A of IEC 60255-1:2009

The manufacturer recommends specific cable types for each input and output port, and any limitations on maximum cable length must be clearly stated It is essential to adhere to the maximum cable length guidelines provided for each test in accordance with the basic standard.

Auxiliary support and monitoring equipment must be connected to the Equipment Under Test (EUT) to facilitate all functions and monitor performance during testing It is essential that this equipment is selected to avoid any negative impact on the test results and remains unaffected by interference during immunity tests If the testing process does influence the auxiliary equipment, appropriate filtering and de-coupling networks should be implemented to ensure the integrity of the test is maintained Detailed values and examples of these networks are provided in the basic standards.

Protection settings and functional settings shall be applied to the EUT with reference to

According to IEC 60255-1, the delay settings must be adjusted to their minimum values Immunity tests should be conducted with the Equipment Under Test (EUT) in both quiescent and, when specified, operated states For current transformer inputs, the most sensitive rating is to be utilized.

Functional tests are essential to ensure the proper operation of the Equipment Under Test (EUT) within its specified accuracy rating, and these tests must be conducted both before and after the immunity tests Additionally, certain individual tests will necessitate the performance of functional tests during the immunity testing process.

The test procedure will specify when certain requirements are necessary For multifunctional relays, manufacturers must designate at least one protection function, typically the main function, to ensure proper operation during EMC immunity tests.

The output of the test generator shall be verified as stated in the basic standard.

Electrostatic discharge

Table 10 – Electrostatic discharge immunity test

Initial measurement The tests shall be carried out in accordance to 7.2.2

Details of mounting/support The EUT is placed in its case or housing in as close to installed conditions as possible

Tests shall be applied as follows:

− the contact discharge method is the preferred method;

− the air discharge method shall only be used when the accessible surfaces of the EUT are non-conducting;

− the direct and indirect application test method shall be used

Application of the discharges See Annex C

Test voltage See Table 3, item 3.2

Measurement and verification during the test

The EUT will have normal performance within the specification limits when energized and subjected to the electrostatic discharges

Tests will be conducted using auxiliary energizing quantities applied to the appropriate circuits, with input energizing quantities set to rated values These input values must remain within twice the assigned error below the transitional state, as outlined in IEC 60255-1:2009, Annex A Given that the occurrence of electrostatic discharges coinciding with a primary fault is deemed unlikely, the impact of electrostatic discharges on the Equipment Under Test (EUT) during its transitional or operating condition is not taken into account.

The test will be conducted at accessible points for the operator during normal service conditions, including communication ports and adjustment settings that require only the removal of the relay cover Adjustments that involve actions beyond simply removing the cover, such as module removal, are excluded from the test.

The application of discharge to equipment points accessible solely for repair and maintenance is not covered by this standard When selecting test points, it is essential to consider specific criteria.

- knobs, push-buttons, switches, communication interface, etc., accessible under normal service;

- points on covers of insulating material where conducting parts are close to the inside of the cover;

- points on conducting parts not belonging to, but placed in the vicinity of, the EUT, when this has an insulating cover

To achieve reproducible results, it is recommended that the selected test points are specified by the manufacturer (see Annex C)

Testing shall be satisfied at all levels given in Table 3, item 3.2

Acceptance criteria See Table 3, item 3.2.

Radiated interference

Table 11 – Radiated interference immunity test (frequency sweep)

Details of mounting/support The EUT is placed in the calibrated test field

Frequency range to be swept See Table 3, item 3.1

The dwell time for each frequency must be set to 0.5 seconds If the equipment under test (EUT) operates for longer than 0.5 seconds, the dwell time should be extended to ensure the EUT can function properly.

Test field strength See Table 3, item 3.1

The EUT will have normal performance within the specification limits when energized and subjected to the electromagnetic field

Tests will be conducted using auxiliary energizing quantities applied to the relevant circuits, with input energizing quantities set to rated values The impact of disturbances on the relay during its transitional or operating state is not taken into account Input energizing quantities must remain within twice the assigned error of the transitional state, as outlined in IEC 60255-1:2009, Annex A.

Acceptance criteria See Table 3, item 3.1

Table 12 – Radiated interference immunity test (spot frequencies)

Details of mounting/support The EUT is placed in the calibrated test field

Spot frequencies See Table 3, item 3.1

Duty cycle See Table 3, item 3.1

Dwell time The dwell time at each spot frequency shall be sufficient for the EUT to change from the quiescent state to the operate state

The EUT is capable of correct operation and reset in the presence of an electromagnetic field from a radiation source at the given spot frequencies

In each spot frequency test, the input energizing quantities must be adjusted to transition the Equipment Under Test (EUT) from its normal energized state to the operated state, maintaining this condition until the EUT functions correctly Subsequently, the input energizing quantities should be readjusted to facilitate the reset of the EUT.

Electrical fast transient

Table 13 – Electrical fast transient immunity test

All auxiliary equipment used to provide the EUT with signals for normal operation, and to verify the correct operation of the EUT, shall be decoupled

The fast transient/burst test is not applicable to the functional earth port when connecting to cables that have a total length of less than 3 meters, as specified by the manufacturer.

The fast transient/burst test is unsuitable for communications ports when interfacing with permanently connected cables that, according to the manufacturer's specifications, have a total length of less than 3 meters.

Where the EUT is mounted in a cubicle, the tests may be conducted in the cubicle No test shall be performed on interconnecting cables within the same cubicle

AC current and voltage ports

CDN CDN Capacitive coupling clamp Capacitive coupling clamp Capacitive coupling clamp Capacitive coupling clamp

Test voltage See Table 4, item 4.2, Table 5, item 5.2, Table 6, item

Repetition frequency See Table 4, item 4.2, Table 5, item 5.2, Table 6, item

Test wave form characteristic See Table 4, item 4.2, Table 5, item 5.2, Table 6, item

The EUT will have normal performance within the specification limits when energized and subjected to the disturbance

Tests will be conducted using auxiliary energizing quantities applied to the relevant circuits, with input energizing quantities set to rated values The impact of this disturbance on the relay during both its quiescent and operating states will be evaluated Input energizing quantities must remain within twice the assigned error of the transitional state, as outlined in IEC 60255-1:2009, Annex A.

The test voltage shall be applied in common mode to one port at a time for at least 1 min for each polarity

Acceptance criteria See Table 4, item 4.2, Table 5, item 5.2, Table 6, item

Slow damped oscillatory wave

Table 14 – Slow damped oscillatory wave immunity test

All auxiliary equipment used to provide the EUT with signals for normal operation, and to verify the correct operation of the EUT, shall be decoupled

Where the EUT is mounted in a cubicle, the tests may be conducted with the EUT in the cubicle

The damped oscillating wave will exhibit an envelope where the 5th peak exceeds 50% of the initial peak value, while the 10th peak will fall below 50% of the initial peak value.

Voltage rise time See Table 4, item 4.3, Table 5, item 5.3 and Table 6, item 6.3

Voltage oscillation frequency See Table 4, item 4.3, Table 5, item 5.3 and Table 6, item 6.3

Source impedance See Table 4, item 4.3, Table 5, item 5.3 and Table 6, item 6.3

Frequency repetition See Table 4, item 4.3, Table 5, item 5.3 and Table 6, item 6.3

Test level See Table 4, item 4.3, Table 5, item 5.3 and Table 6, item 6.3

CM/DM with CDN CM/DM with CDN

Measurement and verification during the test c

The EUT will have normal performance within the specification limits when energized and subjected to the disturbance

The acceptance criteria are detailed in Tables 4, 5, and 6 A common mode test must be conducted between each independent port and earth, as well as between each independent port and all other independent ports connected to earth The damped oscillatory wave test is not applicable for communication ports interfacing with cables that are not permanently connected or have a total length of less than 3 meters, as specified by the manufacturer Additionally, if the operating time of the Equipment Under Test (EUT) exceeds 2 seconds, the test voltage must be applied for a duration longer than the actual operating time of the EUT It is also important to maintain a minimum time interval between successive tests.

Surge

The Equipment Under Test (EUT) must be configured according to section 7.2.2 and tested individually on a bench or tabletop If the EUT is installed in a cubicle and used alongside other devices, testing may occur within the cubicle It is essential to adhere to any insulating support requirements for the EUT as specified in the basic standard.

The support equipment must be configured according to section 7.2.2, ensuring compliance with the basic standard's requirements for insulating supports for both the support equipment and interconnecting cables.

The connections between the Equipment Under Test (EUT) and the test generator must not exceed 2 meters Additionally, with the exception of testing the communications port, the connections between the EUT and the coupling/decoupling networks should also remain under 2 meters.

The maximum cable length of screened interfaces shall be not more than 20 m

Application ports and values of source impedance and coupling capacitance a b c d

AC current and voltage ports

Test waveform characteristic See Table 4, item 4.4, Table 5, item 5.4, Table 6, item

Test voltages See Table 4, item 4.4, Table 5, item 5.4, Table 6, item

The EUT will have normal performance within the specification limits when energized and subjected to the surge immunity test

The tests shall be carried out with auxiliary energizing quantities applied to the appropriate circuits, using input energizing quantities equal to rated values

The impact of this disturbance on the relay during its transitional or operating state is not taken into account According to IEC 60255-1:2009, Annex A, the input energizing quantities must remain within twice the assigned error of the transitional state.

The number of tests shall be at least five positive and five negative surges The repetition rate shall be a maximum of 1 surge/min

Because of the possibility that the EUT has non-linear current-voltage characteristics, all lower test voltages up to and including the maximum test voltage selected shall be satisfied

Surges will be applied between line to earth and line to line as necessary During line to earth testing, the test voltage will be successively applied between each line and earth.

The acceptance criteria outlined in Tables 4, 5, and 6 specify that no testing is required for ports interfacing with cables shorter than 10 meters, as per the manufacturer's specifications Additionally, line-to-line testing is not recommended for input and output ports connected to twisted pair screened cables Furthermore, the surge application is designed to replicate a lightning strike, characterized by a short-duration, high-energy pulse.

Low impedance high sensitivity circuits can generate a start signal when a pulse is applied, indicating that the relay (EUT) has correctly interpreted the pulse according to its design Manufacturers must specify any necessary time delays or setting limitations to ensure immunity to surge pulses If the coupling capacitor affects the operation of the circuit under test, alternative coupling methods, such as gas discharge tubes or varistors, are permitted as outlined in the basic standard, and these should be documented in the test report For unscreened communication ports, coupling should follow the specifications in Table 6, item 6.4.

Conducted interference

Table 16 – Conducted interference immunity test (frequency sweep)

All auxiliary equipment used to provide the EUT with signals for normal operation and to verify the correct operation of the EUT, shall be decoupled

Where the EUT is mounted in a cubicle, the test may be conducted in the cubicle

No test shall be performed on interconnecting cables within the same cubicle

Application ports/methods For coupling method on different application ports, see

Test level See Table 4, item 4.1, Table 5, item 5.1, Table 6, item

Frequency range to be swept See Table 4, item 4.1, Table 5, item 5.1, Table 6, item

Amplitude modulation See Table 4, item 4.1, Table 5, item 5.1, Table 6, item

The dwell time at each frequency must be at least 0.5 seconds If the equipment under test (EUT) operates for longer than 0.5 seconds, the dwell time should be extended to ensure the EUT can function properly.

Test level See Table 4, item 4.1; Table 5, item 5.1; Table 6, item

The EUT will have normal performance within the specification limits when energized and subjected to the conducted disturbance

Tests will be conducted using auxiliary energizing quantities applied to the relevant circuits, with input energizing quantities set to their rated values The impact of disturbances on the relay during its transitional or operating state is not taken into account Input energizing quantities must remain within twice the assigned error of the transitional state.

Acceptance criteria See Table 4, item 4.1; Table 5, item 5.1; Table 6, item

Table 17 – Conducted interference immunity test (spot frequencies)

All auxiliary equipment used to provide the EUT with signals for normal operation and to verify the correct operation of the EUT, shall be decoupled

Where the EUT is mounted in a cubicle, the test may be conducted in the cubicle

No test shall be performed on interconnecting cables within the same cubicle

Application ports/methods For coupling method on different application ports see

Spot frequencies See Table 4, item 4.1; Table 5, item 5.1; Table 6, item

Amplitude modulation See Table 4, item 4.1; Table 5, item 5.1; Table 6, item

Duty cycle See Table 4, item 4.1; Table 5, item 5.1; Table 6, item

Dwell time The dwell time at each spot frequency shall be sufficient for the EUT to change from the quiescent state to the operate state

Test level See Table 4, item 4.1; Table 5, item 5.1; Table 6, item

The EUT is capable of correct operation and reset in the presence of the conducted disturbance at the given spot frequencies

During each spot frequency test, the input energizing quantities must be adjusted to transition the Equipment Under Test (EUT) from its normal energized state to the operated state, and maintained until the EUT functions correctly Subsequently, the input energizing quantities should be readjusted to reset the EUT.

Acceptance criteria See Table 4, item 4.1; Table 5, item 5.1; Table 6, item

Power frequency immunity on d.c binary inputs

Table 18 – Power frequency immunity test

Details of mounting/support The EUT is placed in normal operating condition

Application ports and values of source impedance and coupling capacitance a b See Table 6, item 6.5

Test frequency Rated frequency, e.g 16,7 Hz, 50 Hz or 60 Hz

Test voltage See Table 6, item 6.5

The tests shall be carried out with auxiliary energizing quantities equal to rated values applied to the auxiliary d.c power supply port

To ensure correct operation, the test voltage must be applied only when the d.c binary input is not energized If the d.c binary input features a software or hardware controllable delay, the test voltage should initially be applied with the delay set to its minimum In the event of a failure, the delay should be incrementally increased, and the test voltage reapplied until successful The final delay value for the d.c binary input must be documented in the test report.

NOTE 1 Annex A contains technical information for the power frequency immunity tests

NOTE 2 Annex B contains background information for the power frequency immunity tests a The differential mode test is not required on d.c binary input ports which, according to the manufacturer’s functional specification, always have an interface via multi-core screened or twisted pair (screened or unscreened) cables b Unless otherwise stated, no test is required for d.c binary input ports interfacing with cables whose total length according to the manufacturer’s functional specification is always less than 10 m.

Power frequency magnetic field

Table 19 – Power frequency magnetic field immunity test

Details of mounting/support The EUT is placed in the magnetic field of a 1 m × 1 m induction coil

Test frequency Rated power frequency of the EUT, which is used where the EUT is intended to be installed, (e.g 50 Hz or

The EUT will have normal performance within the specification limits when energized and subjected to the magnetic field

Voltage dips and voltage interruptions on power supply voltage (a.c

Table 20 – Voltage dips and voltage interruptions test

Accessories shall be connected according to manufacturer’s specification

EUT shall be in a quiescent state

Half of the binary inputs and half of the output relays shall be energized

Communication modules, if any, shall be activated

Selection of application points The tests shall be applied to power supply terminals

Test levels See Table 4, item 4.5 and item 4.6

The voltage in this standard uses the rated voltage for the EUT as a basis for voltage test level specification

Where the EUT has a rated voltage range, the test procedure shall be applied at the lowest voltage declared in the voltage range

Example: EUT with a rated voltage range of 100 V to

For equipment under test (EUT) powered by a direct current (d.c.) supply, only the relevant tests for d.c should be conducted Conversely, for EUT designed for alternating current (a.c.) supply, only the applicable a.c tests are required In cases where the EUT can operate with both a.c and d.c power supplies, it is essential to perform tests for both types of power.

Acceptance criteria See Table 4, item 4.5 and item 4.6.

Voltage ripple on d.c power supply voltage

Test level See Table 4, item 4.7

During testing, the measurement and verification process utilizes the rated voltage of the Equipment Under Test (EUT) as the foundation for specifying voltage test levels If the EUT has a rated voltage range, the testing procedure must be conducted at both the lowest and highest voltages within that range.

Example: EUT with a rated voltage range of 100 V to 200 V ± 20 % should be tested at 80 V and 240 V

Gradual shut down / start-up tests

Table 22 – Gradual shutdown and start-up test

Test level See Table 4, item 4.8

During testing, the voltage measurement and verification process utilizes the rated voltage of the Equipment Under Test (EUT) as the foundation for specifying voltage test levels If the EUT has a rated voltage range, testing should be conducted at the lowest voltage within that range.

Example: EUT with a rated voltage range of 100 V to 200 V ± 20 % should be tested at 80 V (see Figure 2)

Ue rated auxiliary power supply voltage

Ue min lower limit of Ue

Figure 2 – Gradual shut down/start-up test

Emission

The EUT shall satisfy the requirements of this specification if conducted and radiated emissions during the tests do not exceed the limits given in Table 1 and Table 2

The evaluation results of emissions from EUTs with at least one of each type of identical module can be extended to configurations with multiple identical modules, as emissions from these modules are not additive This principle also applies to protection equipment consisting of several identical measuring relays.

Immunity

Table 23 – Acceptance criteria for immunity tests

Criteria Function Conditions for acceptance

A Protection Normal performance within the specification limits, during and after the test

Command and control Normal performance within the specification limits, during and after the test

Measurement No degradation during test

Integral human-machine interface and visual alarms No degradation or no loss of function during test No loss of stored data

Data communication b Possible bit error rate increase but no loss of transmitted data

Binary input, binary output and output contacts No unwanted change of status is allowed during the test a

B Protection Normal performance within the specification limits, during and after the test

Command and control Normal performance within the specification limits, during and after the test

Measurement Temporary degradation during test, with self-recovery at the end of the test No loss of stored data

Integral human-machine interface and visual alarms Temporary degradation or loss of function during test, with self- recovery at the end of the test No loss of stored data

Data communication b Possible bit error rate increase but no loss of transmitted data

C Protection Temporary loss of function provided the function is self- recoverable

No unwanted operation shall be observed

Command and control Temporary loss of function provided the function is self- recoverable

No unwanted operation shall be observed

Measurement Temporary loss of function provided the function is self- recoverable

Integral human-machine interface and visual alarms Temporary loss of function provided the function is self- recoverable

Data communication b Temporary loss of function, provided the function is self- recoverable Possible loss of transmitted data

Manufacturers must include any degradation specifications used during or after testing in the product documentation provided to users For binary inputs, the minimum filtering value that ensures a successful test must be clearly stated This excludes communication ports related to protection or control functionality, for which separate acceptance criteria apply.

A test report giving the test procedures and results shall always be produced

A comprehensive test report must include essential information such as a title (e.g., "test report"), the laboratory's name and address along with the testing location if different, a unique identification number for the report, and page identifiers to recognize the report's pages and its conclusion Additionally, it should contain the client's name and address, a clear description and identification of the Equipment Under Test (EUT), the test dates, results with appropriate measurement units, and the names, functions, and signatures of the individuals authorizing the report If applicable, a statement indicating that the results pertain solely to the EUT should also be included.

Test reports must encompass essential details such as the test conditions, methods employed, measuring equipment utilized, and the final test conclusion indicating pass or fail Additionally, when relevant, the reports should include any necessary opinions and interpretations.

Power frequency immunity tests on binary inputs

Power frequency immunity tests, as outlined in IEC 61000-4-16, aim to verify the proper operation of the equipment under test (EUT) when exposed to short-duration, conducted power frequency disturbances These disturbances can occur in both common and differential modes and are applied to d.c binary inputs at the EUT's rated frequency, such as 16.7 Hz, 50 Hz, or 60 Hz.

The testing of pilot wire schemes between substations is not covered by these tests

Class A test levels are designed for substations experiencing high earth fault currents, where standard wiring practices permit d.c binary inputs to connect to primary plant auxiliary contacts through 'open' loops An open loop configuration, where the go and return leads are routed in separate multi-core cables, can lead to significantly different paths This arrangement creates a substantial area of magnetic flux linkage with the primary earth fault current, resulting in elevated levels of power frequency interference.

Class B test levels are applicable to either:

• substations with low earth fault currents, for example substations which use isolated or

Proper wiring practices ensure that d.c binary inputs are not connected in 'open' loops This is achieved by utilizing both go and return wires within the same multi-core cable, which maintains identical routes for both As a result, the area of magnetic flux linkage with the primary earth fault current is minimized, significantly reducing power frequency interference levels.

Where the test frequency is not that of the available mains distribution network, an alternative test generator will have to be used, for example as described in 6.1.3 of

The test generator typically consists of a variable transformer connected to the mains distribution network and an isolation transformer The generator shall have the following characteristics:

Waveform: Sinusoidal, total harmonic distortion less than 10 %

Open circuit output voltage range: 100 V to 300 V r.m.s ( ± 10 %)

Frequency: Selected rated frequency ( ± 0,5 Hz)

On/off output voltage switching: Synchronized at zero crossing (0° ± 10°) or increased from zero / decreased to zero (see A.4.3)

A.3.3 Verification of the test generator

In order to ensure that the results when using different test generators can be meaningfully compared, the following characteristics of the generator shall be calibrated or verified:

– open circuit output voltage accuracy

Verifications must be conducted using a voltage probe and oscilloscope or similar measuring instruments that have a minimum bandwidth of 1 MHz, ensuring an accuracy of better than ± 5%.

The coupling networks enable the test voltage to be applied in both common and differential mode (see Figures A.1, A.2 and A.3 for typical test set-ups)

The network comprises a series connection of a resistor and a capacitor, with component values specified in Table 6, item 6.5 Each pair of capacitors and resistors must be matched with a tolerance of 1%.

Figures A.1 and A.2 illustrate standard test configurations for differential mode tests, while Figure A.3 depicts a typical setup for common mode tests It is essential that the connections between the Equipment Under Test (EUT) and the coupling network do not exceed 2 meters.

The EUT, along with its auxiliary and test equipment, must consistently meet safety earthing requirements Furthermore, the EUT should be connected to the earthing system as specified by the manufacturer.

All auxiliary equipment used to supply signals for the normal operation of the Equipment Under Test (EUT) and to verify its correct functioning must be decoupled to ensure that the test voltage does not interfere with the auxiliary equipment.

To ensure the proper operation of the Equipment Under Test (EUT) as per specifications, it is essential to connect all necessary auxiliary equipment, including communication devices, modems, and printers Additionally, this equipment is crucial for facilitating data transfer and verifying the functionality of the EUT.

However, as far as possible the number of cables to be monitored will be limited by taking into consideration only the representative functions

The test generator must be connected to the d.c binary input port of the Equipment Under Test (EUT) If this port includes several identical circuits, only a specified number of these circuits, as determined by the manufacturer, are required to be tested to ensure the EUT operates correctly.

The test voltage shall be applied for at least 10 s so that the EUT’s operating performance can be verified The test voltage shall be applied as shown in Figures A.1, A.2 and A.3

In the absence of a test generator with zero crossing synchronization, it is essential to gradually increase the test voltage from zero to the desired level at the beginning of the test and to decrease it back to zero at the conclusion These initial and final phases should not be counted as part of the actual test duration, and each phase must last less than 20% of the total time the required test voltage is applied.

Figure A.1 – Example of Class A differential mode tests

Figure A.2 – Example of Class B differential mode tests

Figure A.3 – Example of common mode tests

Background information for power frequency tests

Conducted interference voltages arise from various interference sources and can be transmitted to supply cables, signal cables, and the earthing of measuring relays and protection equipment through inductive or capacitive coupling.

Tiêu đề	Measuring Relays and Protection Equipment – Part 26: Electromagnetic Compatibility Requirements
Chuyên ngành	Electrical and Electronics Engineering
Thể loại	standard
Năm xuất bản	2013

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Số trang	96
Dung lượng	691,03 KB