Control Strategy of Voltage Source PWM Rectifiers Under Unbalanced Voltage Conditions

Current control strategies of voltage source pulse width modulation（PWM） rectifiers under unbalanced voltage conditions at home and abroad were researched.The disadvantages in current control strategies were pointed out.In order to improve the control performances of voltage source PWM rectifiers under unbalanced voltage conditions,a new passivity-based control strategy was proposed according to passivity-based control theory.Passivity-based control strategy can overcome the defects of the current control strategies and eliminate or restrain all harmonics of rectifiers.The new strategy only need the real time value of voltage and current,don’t need detection and treatment of positive and negative sequence components of all harmonics.Then passivity based control strategy has very strong robustness and ease realization.Simulation results show that passivity based control strategy is feasible.