Research of PWM rectifier under unbalanced input voltages control method

Traditional control method of PWM(Pulse Width Modulation) rectifier has good dynamic and steady-state performance, But when PWM Rectifier worked under unbalanced voltages, various harmony powers occurred. Quality of output voltage and input current had been affected. Analyze unbalanced voltage and current through the method of symmetrical component, and two vector-oriented control strategy based on positive and negative voltage -oriented respectively is proposed in this paper. The relation among voltage, current and power was used to get the current references under positive and negative d-q axis. The result of simulation and experiment shows that new methods can keep the DC voltage steady and the other can control the input current sine.