A fully digital vector current control of three phase shunt active power filters

The most important issues in implementing shunt active power filters are to obtain accurate information about harmonic currents, and to inject the appropriate compensating currents into the AC lines. This paper presents a space vector control technique of the compensating currents with low switching frequency. The proposed control strategy and the computation method of the current references, based on instantaneous reactive power theory, are entirely performed digitally in a PC-based control system.