Maintenance of power capacitor (1) Precautions for capacitor operation: 1) Under normal conditions, Inner Mongolia Electric Power Design For power failure operation of the whole station, the capacitor circuit breaker shall be opened first, and then the outgoing circuit breakers shall be opened; When power is restored, the sequence is reverse. 2) In case of an accident, the circuit breaker of the capacitor must be opened after the power failure of the whole station. 3) After the circuit breaker of shunt capacitor bank trips, forced power transmission is not allowed; After the fuse is blown, it is not allowed to replace the fuse for power transmission until the cause is found out. 4) Shunt capacitor banks, and it is forbidden to switch on with charge; Re closing must be carried out 3 minutes after opening. 5) The circuit breaker with parallel resistance shall not be closed by manual operating mechanism.

6) The exposed conductive part of the high-voltage capacitor bank shall have a mesh barrier. When conducting external inspection, it is forbidden to open the barrier of the capacitor bank in operation.

7) Any capacitor bank with rated voltage shall not be switched on with charge. Each time it is switched off, it shall be switched on again after three minutes of short circuit (a little time after discharge).

8) Replace the fuse of the capacitor when the capacitor has no voltage. Therefore, discharge the capacitor before proceeding.

(2) Troubleshooting

1) When the capacitor sprays oil, explodes and catches fire, the power supply shall be cut off immediately, and sand or dry fire extinguisher shall be used to extinguish the fire.

2) The circuit breaker of the capacitor tripped, but the fuse was not blown. Which one is good for Inner Mongolia Electric Power Design After the capacitor is discharged for 3 minutes, check the external conditions of the circuit breaker, current transformer, power cable and capacitor. If no abnormality is found, it may be caused by external fault or voltage fluctuation, so it can be put into trial operation; otherwise, further comprehensive power on test shall be conducted for the protection.

3) When the fuse of the capacitor is blown, it shall be reported to the dispatcher on duty. After obtaining the consent, the power supply shall be cut off and the capacitor shall be discharged. After that, the external inspection shall be carried out first, such as whether there are flashover marks on the outside of the bushing, whether the shell is deformed, whether there is oil leakage, and whether the grounding device is short circuited. Then, the insulation resistance between poles and between poles and ground shall be measured with a megger. If no fault is found, replace the fuse and continue to put it into operation. If the fuse is broken after power transmission, the fault capacitor shall be exited.

4) To deal with the faulty capacitor, first disconnect the circuit breaker of the capacitor and pull the disconnectors on both sides of the circuit breaker. After the capacitor bank is discharged by the discharge resistance, some residual charges may not be discharged completely for a while, so a manual discharge should still be carried out. When discharging, first connect the grounding terminal of the grounding wire, and then discharge the capacitor for many times with the grounding rod until there is no spark and sound of discharge. However, before touching the fault capacitor, you should also wear insulating gloves. Inner Mongolia Electric Power Design Co., Ltd. will first use a short circuit to short the two poles of the fault capacitor, and then manually remove and replace it.