High performance compensation current control strategy of single-phase SVG

To deal with the characteristics of single-phase grid a double-loop control strategy of PI and repetitive control compound controller(PI+REP) is introduced to improve the compensation performance of single-phase static var generator(SVG).The PI controller is designed according to the mathematics model of system.And the outer repetitive controller is designed based on the frequency characteristics of inner closed-loop.It can combine superior dynamic performance and robustness of PI controller at low frequency with high tracking accuracy towards periodic signals of the repetitive one,and greatly improve the output performance of single-phase SVG.Frequency characteristics analysis indicates that the system phase lag caused by conventional PI controller is eliminated at the fundamental frequency and less than 4.5° within 500 Hz.Simulation and experimental results show that the accuracy of reactive power compensation and ability of harmonic suppression of single-phase SVG are both improved by using proposed control strategy.