Factors that interfere with the microcomputer relay protection tester:

1. Electrostatic discharge interference

In a dry environment, workers’ clothing may carry high voltages. In the case of wearing insulated boots, they can carry electric charges to far away, so when workers touch electronic devices, they will discharge them. The degree of discharge varies with the grounding condition of the equipment and the environment. In severe cases, the electronic components will be burned and the system of the microcomputer relay protection tester will be destroyed.

2. Radiation interference

There are often walkie-talkies and mobile communication tools around the power system, so strong radiating electric fields and corresponding magnetic fields will be generated around it. The changing magnetic field is coupled to the loop of nearby weak electronic devices. The loop will induce a high-frequency voltage to form a false signal source, which will cause the microcomputer relay protection tester to operate incorrectly.

3. Lightning strike

When the grounding component or lightning arrester of the substation is struck by lightning, because the ground grid of the substation is high impedance or the ground wire from the equipment to the ground grid is high impedance, the high-frequency current generated by the lightning strike will be caused in the ground grid system of the substation. The increase of the transient potential may cause the malfunction of the microcomputer relay protection tester or damage the sensitive equipment and the control circuit.

4. High frequency interference

If the operating speed of the power system in the isolating switch is slow, arc flashover will occur between the two contacts of the isolating switch during operation, resulting in operating over-voltage and high-frequency current. When the high-frequency current passes through the bus, it will be on the bus. Strong electric and magnetic fields are generated around, which will cause interference to related secondary circuits and secondary equipment. When the interference level exceeds the allowable interference level of the logic components of the device, it will cause abnormal operation of the microcomputer relay protection tester, thereby causing The working logic or export logic of the entire device is abnormal, causing great damage to the stability of the system. High-frequency current flows into the ground network through the grounding capacitor device, which will cause the ground potential to rise.