Power capacitor operation and maintenance - Database & Sql Blog Articles

SMD aluminum electrolytic capacitor

Photocoupler

Power capacitors are mainly used to compensate reactive power and improve power factor in power distribution systems. The load in the power supply system is mostly inductive. Usually, the inductor current lags behind the voltage by 90°. If the power capacitor is connected to the power supply system, a capacitor current is generated in the loop. The current is ahead of the voltage by 90°. At the voltage, the current on the inductor is exactly opposite to the current on the capacitor, thereby canceling a portion of the inductive current or compensating for a portion of the reactive current.
1. Operation of Power Capacitors In the use of power capacitors, we must pay attention to its safe operation and economic operation. It is particularly noteworthy that the power capacitor should be operated at rated voltage, not exceeding 1.05 times the rated value, but allowed to operate for 1.1 hours at 1.1 times the rated voltage. If the capacitor used exceeds 1.1 times the rated value, it should be stopped. . When the voltage is too high, the power capacitor is overloaded, causing internal components to overheat or breakdown. On the other hand, the power loss caused by over-compensation or reactive reversal after the electrical equipment is stopped should be avoided.
The general ambient temperature of power capacitor operation is between -20~+45°C. If the temperature is too high or too low, it will easily cause the phenomenon of bulging and oil leakage of the power capacitor, and ensure that the indoor humidity should not exceed 80%.
2. Maintenance of power capacitors In order to ensure the normal operation of power capacitors and prolong their effective service life, attention should be paid to the maintenance of power capacitors in daily operation.
(1) Appearance inspection For the visual inspection of the running power capacitor, look at whether there is fuel injection or oil leakage, whether there is a drum belly, whether there is cracking, whether the terminal is overheated, and if the above abnormality is found. Stop using it immediately to avoid accidents.
(2) Checking the voltage value During the operation of the power capacitor, the voltage fluctuation may occur due to the change of the power supply load. In order to ensure its safe operation, the automatic switching device should be used as much as possible. If the fault occurs automatically, manual operation is required, which requires the operator to load according to the load. The situation is converted, otherwise overcompensation or reactive reversal will occur.
(3) The current value check is to extend the service life of the capacitor. The power capacitor should be operated at the rated current, but it is allowed to operate at 1.3 times of the rated value. If it exceeds 1.3 times, it should be stopped because of excessive current. When passing through a power capacitor, it will cause the capacitor to burn out.