When CKSG series three phase series filter electric reactor is making capacitive reactive power, it is always affected by harmonic current, switching-on, inrush current and switching overvoltage, causing damage to capacitance and decreasing power factor. Therefore, a three phase filter electric reactor should be added on the front end of the capacitor to suppress and absorb harmonic wave, protect capacitor, avoid the influence caused by harmonic voltage and current and impulse voltage and current, improve power quality and increase system power factor and prolong capacitor life span.