Control characteristic of three-phase voltage-source PWM rectifier

Based on the working principle of three-phase voltage-source PWM rectifier,its four-quadrant operating states are studied.It is concluded that,the grid side of PWM rectifier is presented as a current source with controllable current and power factor,which makes the PWM rectifier able to easily switch its operating state over from one to another.To meet the requirements of power factor control at grid side,PWM rectifier must work in Boost state,i.e.the ratio of DC voltage to AC input voltage should be greater than the critical step-up coefficient.The current control strategy of three-phase PWM rectifier is proposed based on space vector arithmetic: the unity power factor control mode when the step-up coefficient is bigger and the lagged power factor control mode when the coefficient is smaller.A hardware platform of three-phase voltage-source PWM rectifier based on DSP controller is designed and built up,and the experimental results validate its operating features and the correctness of the proposed control strategy.