UPQC harmonic current detection method based on ultra-short feedback predictive PI control strategy

In parallel active power filter (PAPF) harmonic current detection methods of unified power quality conditioner (UPQC), the traditional ip − iq detection method has the problems such as poor anti-jamming ability in phase locked loop circuit and hysteresis. This paper proposes a ultra-short feedback predictive PI control strategy based on ip − iq for harmonic current detection. Under the research of predictive PI control algorithm and endocrine hormone feedback mechanism, the controller which combines predictive PI control with ultra-short feedback control is presented for harmonic current detection. The PAPF simulation of UPQC is operated in the distributed grid with nonlinear loads. The simulation results illustrate that the compensation performance based on ultra-short feedback predictive PI control strategy is superior to conventional ip − iq algorithm. Therefore the improved harmonic current method promotes dynamic compensation ability, and provides a new control strategy for UPQC in the distributed grid.