While a large number of modern power electronic equipment used(such as: variable frequency drives, etc.) , the nonlinear current generated by harmonic way affect the power grid and to increase the power load.
The capacitor and transmission transformer in traditional system of pure power factor correction capacitors connected to the resonant circuit .Resonance may cause capacitor overload ,which is bad for measuring and controlling the system of interference,voltage-distortion, harmonic amplification.
The use of tuning reactors and capacitors in series to form a power factor correction system can be tuned to avoid resonance