Why is there sometimes a power outage after thunder?

First, there are two reasons for the power failure accident during thunder: first, lightning damages the transformer or a component; Second, lightning strikes the high-voltage line, and the protective equipment of the transformer automatically trips.

Second, lightning has the characteristics of large current, high power and strong randomness, which is destructive. The damage of power equipment is mainly caused by direct lightning. Impulse voltage of hundreds of thousands to millions of volts will damage the insulation of generators, power transformers and other electrical equipment, and the switch protection of substations will quickly trip to isolate faults, resulting in power failure of lines, while insulation damage may cause short circuits and lead to fire or explosion accidents.

Thirdly, the sensitivity adjustment of circuit breaker is too sensitive, which is also a reason for lightning trip. When lightning strikes, the insulation resistance between the phase line and the neutral line is too low, and part of the current leaks to the earth through the leakage place, so that the sum of current vectors passing through the zero-sequence current transformer is not zero when the line is normal, which may also cause misoperation and tripping.