A small animal entered the 35kV distribution room in a substation and caused a short circuit between a and B phases in the second section of 35kV positive bus. The bus differential protection action in the second section of 35kV positive bus caused the main transformer trip and the power loss of the second section and seven outgoing lines of 35kV positive bus.

After careful inspection, it was found that there was flashover trace in Zhongyuan 2219 switch and rheology, and a cat was arrested in 35kV distribution room. After more than 7 hours of full-scale repair, all of them returned to normal operation.

case analysis

1. The door of 35kV distribution room is not closed tightly, which is the direct cause of the fault of 35kV bus caused by small animals entering, reflecting the operators' weak safety awareness of preventing small animals in winter;

2. The operator on duty is not proficient in business, so that the fault point can be found after a long time, which to some extent delays the recovery of power transmission time.

Case countermeasures

1. If it is found that the on-site staff do not close the door immediately, it will be treated as serious violation of regulations;

2. Carry out overall inspection on all doors, locks, internal and external holes at the inlet and outlet of the high-voltage distribution room of the substation, and solve the problems as soon as possible to ensure that they are in good condition;

3. Strengthen the training of operators on business technology and accident handling, improve the familiarity with the scope of relay protection, and improve the level of accident handling.

We can often hear about various accidents caused by small animals entering the substation and distribution room. In order to effectively avoid these accidents, the power and electrical management department must take effective measures to prevent such accidents.