Since operation of the hoisting system in 3# main shaft at Huo Ge Qi Copper Mine

the power factor at low speed is very low and harmonic current is bigger because the system is DC equipment and thyristor of the speed regulation device adopts gate pole phase shift trigger control

which causes distortion of grid voltage

occurrence of electricity tariff adjustment and

at the same time

the power supply is polluted by the harmonics. Adoption of MSVC-L type dynamic reactive power compensation and harmonic control device in the system enhances the voltage quality

improves power factor

avoids occurrence of power price adjustment

and creates economic benefits.