Protection Device: CSC-103 Line Protection Device

Test Equipment: Relaystar-Z70 Handheld Digital-analog Integrated Relay Protection Tester

High-speed distance protection determines the operating time of the protection device mainly based on measuring the impedance or distance between the fault point and the installation location of the protection device. It is especially suitable for the near-end fault protection of EHV transmission lines. When the short-circuit point is close to the protection installation location, the measured impedance is small and the operating time is short; when the short-circuit point is far from the protection installation location, the measured impedance increases and the operating time extends, which ensures that the protection selectively trips the faulty line with high sensitivity and reliability.

This paper introduces the test of CSC-103 high-speed distance protection using Relaystar-Z70 Handheld Digital-analog Integrated Relay Protection Tester, with attention to distinguishing it from the distance protection Zone I test.

1. Protection-related Settings

1. Setting of Protection Fixed Value Control Word (Distance Protection Part)

2. Protection Press Plate Setting 

Set the "Distance Protection" soft press plate to "1", and set all other functional soft press plates to "0".

2. Test Wiring

△ Wiring Schematic Diagram

Relaystar-Z70 Handheld Digital-analog Integrated Relay Protection Tester is equipped with protection, merging unit, intelligent terminal testing functions and network analyzer digital protection analysis function. Connect Relaystar-Z70 to the protection device to output SV via optical fiber, and receive the operating time sent by the protection device via GOOSE at the same time. The tester is connected to the direct sampling and direct tripping port of the protection device.

3. Test Method

Open the software main interface, select the state sequence test module in the general test category for parameter setting, and simulate the test conditions from the normal state to the fault state.

State 1: Normal State Setting

△ Software Main Interface

△ Normal State Parameter Setting

State 2: Fault State

Simulate phase A grounding fault. The fault voltage UA = (1+k)I*Z = 1.676*2 = 20.004V.Principle for inputting high-speed distance protection of Beijing Sifang: distance protection input, high-speed distance control word input, the whole line length is set to more than 50km, the current is more than 5 times the rated current, the fault time is less than 30ms, and the fault is within 50% of the distance protection Zone I setting value.

△ Fault State Parameter Setting

After completing the above parameter settings, the test can be started. In State 1, check that the protection sampling is normal, and press the trigger button after the PT disconnection is restored, then the protection will operate.

△ High-speed Distance Protection Action Message

4. Test Conclusion

The test method of high-speed distance protection is similar to that of distance protection Zone I, the difference lies in the operating time and action message. The action message of high-speed distance protection is "Distance Protection Zone I Operated" without X value and R value, and the operating time is less than 17ms; while the action message of distance protection Zone I is "Distance Protection Zone I Operated" with X value and R value, and the operating time is about 30ms.

△ Distance Protection Zone I Action Message