Flashover protection is a high-voltage protection mechanism, which can be used for voltage flashover protection, circuit breaker flashover protection, insulating oil flashover protection, etc. in the power system. In short, flashover protection is a manifestation of voltage breakdown.

What is flashover protection Flashover refers to the phenomenon of discharge along the surface of the solid insulator when the gas or liquid dielectric around the solid insulator is broken down. Phenomenon. The application of flashover protection The flashover protection can adjust the flashover voltage in different situations. For example, when using series resonance to conduct AC withstand voltage on high-voltage electrical equipment such as cables and transformers, the flashover voltage can be adjusted freely.

When the AC withstand voltage is set, it is appropriate to set the flashover voltage to 6~8kv. It is appropriate to set the flashover protection of 35kv electrical equipment to 10.5kv. If the flashover protection voltage is set too large or too small, it will give feedback to the actual situation of the tested object. influential. In addition, flashover protection is also affected by distance and humidity. For example, high voltage in a humid environment is easy to discharge moisture in the air. If the flashover protection voltage is too low at this time, flashover protection is prone to occur frequently and cannot be tested. If it is too high, when flashover protection occurs, it is directly the breakdown flashover protection of the tested object.

How to define the flashover voltage varies from manufacturer to manufacturer, some are automatically set according to the coefficient relationship with the test voltage, and some are manually defined by the user. There will still be drawbacks, and I personally think manual settings are better. What should I do after flashover protection? Do not continue to measure after flashover protection occurs, disconnect the power supply of the test instrument, check the safety distance of each component and node, adjust the distance if the distance is too close, and then use 5000V insulation resistance to measure the Ground insulation resistance, if the insulation resistance is less than 0.5MΩ, then the cable may have a breakdown fault. At this time, the high-voltage test cannot be performed again, otherwise the measurement can be continued.