A Control Strategy for Multi-modular Shunt Active Power Filters Applied to High-power Systems

A multi-modular control strategy and an adaptive harmonic detection algorithm are proposed for shunt active power filters(APFs) to compensate for harmonic currents of high-power nonlinear loads.The adaptive harmonic detection algorithm can effectively suppress the impacts of harmonic voltages as well as efficiently track the referenced harmonic current.Compared with other approaches,the capacity-based proportional current-sharing control strategy provides flexible compensation and is easy to implement redundant controls.This means that when the compensation level is higher than the total APF capacity,more harmonic currents can be compensated with the proposed control strategy.Finally,the stability of the multi-modular APF is studied.Theoretical analysis and simulation results verify that the proposed control strategy is suitable for compensating high-power harmonic currents and can improve the stability and security of the multi-modular APF system.