Active power filters are connected to the power grid in parallel, continuously monitoring the voltage and current of the compensation target. Through the calculation of the command current operation unit, they utilize wide-frequency pulse modulation signal conversion technology to drive IGBT modules. By injecting a current into the grid that is opposite in phase and equal in magnitude to the grid's harmonic current, the two harmonic currents cancel each other out. This achieves the functions of filtering harmonics and dynamically compensating reactive power, resulting in the desired power current.