Based on comparative analyses of several different topological structures of hybrid active filters

an improvement scheme by reducing fundamental voltage and the output current of the active device is proposed to effectively reduce the capacity of the active device.The parallel scheme of hybrid active filter and high passive filter is adopted to overcome the existing shortcomings

such as shortage of reactive compensation devices

large capacity of the active part and high costs.The graded harmonic detection

switching capacitor bank

the combination of detection methods and feedback correction of harmonic current are used in this scheme to improve the system performance.Through theoretical analyses

it proved its effectiveness and feasibility.