With the increasing application of power electronic rectification, inverter, high-frequency switching power supply, large UPS and other converter devices, electrical energy has been more fully utilized. However, non-linear power devices and electrical equipment cause severely distorted harmonics of the current waveform. The flow of distorted currents in the power grid causes harmonic voltages; harmonics increasingly threaten the safety and stability of the power system, increase power grid losses, and reduce operation. Efficiency has a great impact on the linear load and frequency sensitive users of the same network. Harmonics have been ranked as the three major hazards of the power system with electromagnetic interference and power factor reduction. Research on reducing and eliminating the problems of higher harmonics in the power supply and distribution system has a very positive meaning for improving the quality of power supply and ensuring the safe and economic operation of the power system. .