Test Device: NR Electric PCS-931 Line Protection Device

Testing Instrument: Relaystar-Z70 Handheld Relay Protection Tester

 

△ Relaystar-Z70 Handheld Relay Protection Tester

The Relaystar-Z70 Handheld Relay Protection Tester is an ultra-slim and lightweight digital-analog integrated relay protection tester, which is approximately A4-sized and weighs only 2.7kg. Equipped with a large-capacity lithium battery, it can be used for system testing and rapid analysis of both smart substations and conventional substations.

The optical digital part of the device is developed based on the IEC61850 protocol, supporting the transmission, reception and analysis of 2-channel SV/GOOSE messages. The analog output part adopts high-power controllable power amplifier technology, supporting 3×10A current output and 3×120V voltage output with an output accuracy of up to 0.1%, which meets the testing requirements of various types of substations including smart substations and conventional substations.

Integrating multiple testing and analysis functions, the system can conduct comprehensive functional and performance tests on protection devices, measurement and control devices, merging units, electronic transformers and other equipment. It can simulate user-defined abnormal messages as needed to verify the functional correctness of message receivers such as protection devices and intelligent terminals.

This paper introduces how to use the Relaystar-Z70 Handheld Relay Protection Tester to commission the optical fiber differential protection test of the PCS-931 protection device in conventional substations.

1 Protection-related Settings

1. Protection Setting Value and Control Word Configuration

Serial Number	Setting Name	Value	Serial Number	Setting Name	Value
01	Differential Variation Start Current Setting	0.1A	06	Channel 1 Pilot Differential Protection Enable	1
02	Zero-sequence Start Current Setting	0.2A	07	Channel 2 Pilot Differential Protection Enable	1
03	Differential Operating Current Setting	2A	08	CT Breakage Blocking Differential Protection	1
04	Local Side Identification Code	1	09	Communication A Internal Clock	1
05	Remote Side Identification Code	1	10	Communication B Internal Clock	1

2. Protection Press Plate Configuration

In the "Press Plate Settings", set the "Channel 1 Differential Protection" soft press plate to "1". On the protection panel, put into service the "Differential Protection" function hard press plate, disconnect the "Trip Output" hard press plate, and check that the optical fiber channel 1 of the protection device is in the loopback state.

2 Test Wiring

 

△ PCS-931 Optical Fiber Differential Protection Wiring Diagram

Connect the current output terminals "Ia", "Ib", "Ic" of the Relaystar-Z70 Handheld Relay Protection Tester to the AC current "IA", "IB", "IC" (polarity terminals) of the protection device respectively. Then short-circuit the AC current "IA'", "IB'", "IC'", "IN'" (non-polarity terminals) of the protection device, and connect the "IN" (zero-sequence current polarity terminal) back to the current output terminal "In" of the Relaystar-Z70.

Connect the input contact "A" of the Relaystar-Z70 to the phase-separated trip output contact "Trip A" of the protection device, and connect the "+KM" terminal of the Relaystar-Z70 to the common terminal of the protection device.

3 Optical Fiber Differential Protection Verification

The Relaystar-Z70 software is equipped with multiple test interfaces, which can realize switching between analog quantity mode and digital simulation mode.

 

△ Software Main Interface

 

1. Verify Reliable Non-operation of Differential Protection at 0.95 Times the Setting ValueSimulate a three-phase short-circuit fault. Based on the differential operating current setting of 2.0A, the calculated differential current test value is 2.0×0.95×0.5=0.95A.

In the "State Sequence" menu, add two states: pre-fault and fault.

State 1 Settings: UA​=UB​=UC​=57.735V, IA​=IB​=IC​=0A, both voltage and current are in positive sequence; trigger mode: time trigger, 10s.

 

△ Normal State Parameter Settings

State 2 Settings: UA​=UB​=UC​=57.735V, IA​=IB​=IC​=0.95A, both voltage and current are in positive sequence; trigger mode: time trigger, 100ms.

 

△ Fault State Parameter Settings

Apply the test quantities. After completing the settings, click Run. The Relaystar-Z70 outputs according to the normal state settings for 10s. After 10s, the device automatically switches to the next state and outputs according to the fault state settings for 0.1s.

Test Result: The protection device does not operate, and the Relaystar-Z70 does not collect a trip signal.

2. Verify Reliable Operation of Differential Protection at 1.05 Times the Setting Value

Simulate a three-phase short-circuit fault. Based on the differential operating current setting of 2.0A, the calculated differential current test value is 2.0×1.05×0.5=1.05A.

In the "State Sequence" menu, add two states: pre-fault and fault. The settings for State 1 are the same as the normal state parameter settings above.

State 2 Settings: UA​=UB​=UC​=57.735V, IA​=IB​=IC​=1.05A, both voltage and current are in positive sequence; trigger mode: time trigger, 100ms.

 

△ Fault State Parameter Settings

Apply the test quantities. After completing the settings, click Run. The Relaystar-Z70 outputs according to the normal state settings for 10s. After 10s, the device automatically switches to the next state and outputs according to the fault state settings for 0.1s.

Test Result: The protection device operates with the trip indicator light on, and the Relaystar-Z70 receives the trip signal sent by the protection device. The trip mode in this test is three-phase trip, and the input A port of the Relaystar-Z70 switch quantity measures an operation time of 26ms.

4 Test Conclusion

Based on the test results, the protection performance measured in this test meets the specification requirements at the differential current setting of 2.0A. The protection reliably does not operate at 0.95 times the differential current and reliably operates at 1.05 times the differential current, with the operation time meeting the differential protection requirements.