Robust L_2 Performance Criteria Design for Cascade D-STATCOM

In order to improve the control robustness,a novel robust L2 performance criteria design for cascade distribution static synchronous compensator(D-STATCOM) with disturbances and parametric perturbations was proposed.This paper built up single H-bridge module for cascade D-STATCOM by equivalent circuit conversion,and then equivalent transform of error system of single H-bridge module was adopted so that the influence of parametric perturbations could be converted into part of the periodic disturbances.A novel algorithm by combination of repetitive control and passivity-based control was proposed to realize the robust L2 performance criteria design for cascade D-STATCOM.The reactive current and DC voltage stability control was realized by given instruction current.DC voltage balancing control was realized based on the power exchange among H-bridge modules.The validity and feasibility of this control strategy was verified by simulation results,and have been used on practical engineering of ?5 Mvar,10 kV D-STATCOM.Simulation and practical engineering application results show that this control strategy can completely realize the reactive current,DC voltage stability and balancing control of cascade D-STATCOM with excellent steady characteristic,fast transient response,easy implementation algorithm,strong robustness as well as important practical engineering value.