Passive power filter is mainly used for harmonic control.When there are many rectifiers, converters or other harmonic sources in low voltage power network, there will be substantial level of harmonics which can jeopardize the safe operation of the main transformer and other electrical devices. Passive filter can effectively absorb harmonics, and improve the voltage waveform and power factor of the power system.It can can also suppress the inrush current and switching over-voltage so as to improve the quality of electric energy. The passive filter is composed of capacitor and reactor, which can constitute a low impedance bypass on the main harmonic, such as the third, the fifth and the seventh harmonic, to lead the harmonic current into filtering channels and improve the quality of electric energy.
