The large number of nonlinear loads

harmonic current and low power factor is existed in the metallurgical enterprises.Harmonic current leads the converter of nonlinear load easily damaged: low power factor increases the active power loss and power consumption of enterprises

thus causing the enterprises get fined by the electric company.In this paper

such treatment scheme as automatic switching filter capacitor by using high voltage vacuum contactor is introduced.It is proved by practice that above problem can be well solved

and it would not cause over-compensation of reactive power.Moreover

do not need human to participate in the operation

greatly reducing the operator workload.