Relay protection testing is a very important part of the power system. The purpose of relay protection testing is to verify the reliability, sensitivity, and correctness of different functional protection devices in the power system, ensuring that the faulty equipment can be quickly removed from the system when a fault occurs in the power system, thereby ensuring the stability and safety of the power system. What are the commonly used relay protection tests? Let's introduce it now.
1. Action time test
The action time test is the most fundamental test in relay protection testing. Its main function is to verify whether the response speed of the protection device meets the requirements when detecting abnormal situations. The action time test usually uses the output of current transformers and voltage transformers as input signals, passing the input signal through the protection device to make the device act, recording the action time, and determining whether the protection device meets the requirements.
2. Repeatability test of actions
The main purpose of action repeatability test is to verify whether the protection device has sufficient action repeatability. In actual operation, the protection device may experience misoperation or leakage, which can pose safety hazards to the power system. To avoid these phenomena, we need to verify the absolute reliability of the protection device through action repeatability test of the relay protection device. Generally, the same test is repeated multiple times, Check if the deviation of the data meets the requirements.
3. Stability test
The main function of stability testing is to verify whether the protection device can work stably in the event of a system malfunction. During the operation of the power system, various faults may occur, and different faults may have different effects on the protection device. In this case, we need to verify whether the protection device can work well through stability testing.
4. Sensitivity test
Sensitivity test is a very important test in protection equipment, also known as "accuracy verification". Its main function is to verify whether the protection device can sensitively detect system faults. In the power system, the sensitivity to detect faults is very important, because only when faults occur, can the equipment cut off the equipment running with faults in a timely manner, In order to avoid more serious or large-scale power safety accidents in the system.
5. Action current characteristic test
The action current characteristic test is a very important test in the protection equipment test. Its main function is to verify whether the protection device correctly responds to faults at different current levels. Generally, 0.95 times and 1.05 times the rated value are taken as the reference current for the test. In the power system, different equipment has different rated working currents. Therefore, when conducting the action current characteristic test, It is necessary to conduct tests according to the rated working current of the equipment to verify the working performance of the protection device.
6. Voltage drop test
The voltage drop test is a very important test in the protection device, also known as "voltage protection". Its main function is to verify whether the protection device can operate normally. When a fault occurs in the power system, the voltage will also decrease. Even if the current protection is not activated, it can reliably detect the system fault and remove it when the voltage drops. In the power system, The stability of voltage directly affects the safe operation of the power system, therefore, voltage reduction test is an essential test in relay protection testing.
