When compensating for capacitive reactive power, capacitors are often affected by harmonic currents, inrush currents upon switching on, and switching overvoltages, resulting in capacitor damage and a decrease in power factor. Therefore, it is necessary to install a series reactor in front of the capacitor to resist and absorb harmonics, protect the capacitor, avoid the impact of harmonic voltage and current as well as impulse voltage and current, improve power quality, increase system power factor, extend capacitor life, and ensure safe operation of the power grid.