An active method for suppressing harmonic current of power capacitor

The power capacitor is widely used for power factor correction in a power system. The damage to power capacitor as a result of harmonic pollution has been a problem in recent years. This may result in power interruption or accidents in industries. In this paper, a new power capacitor protection method is proposed. In this method, a low capacity power converter serially connected to the power capacitor to adjust a current flowing through the power capacitor to be approximated as a fundamental sinusoidal waveform, and thereby it can avoid the harmonic resonance generated between power capacitor and the impedance of power system that may damage the power capacitor and adjacent power facilities. A prototype is developed and tested to verify the performance of the proposed method. The test results show that the proposed method has the expected performance