Dynamic Response Optimization for Three-phase Vienna Rectifier with Load Feedfoward Control

This paper proposes a load feedforward digital control scheme to optimize dynamic response of three-phase Vienna rectifier. The transient state of voltage loop in conventional average current mode control is analyzed in detail. In order to reduce overshoot of output voltage, load feedforward control is utilized to compensate voltage loop. The terms of feedforward compensator are derived assuming ideally balanced grid and unity power factor. The moment of load step is detected to increase response speed. To avoid addition distortion to line current waveform, the proposed feedforward variable is only updated at transient and keep constant in steady state. Frequency domain response characteristics are analyzed. Simulation models demonstrate the proposed control strategy and a prototype of 3kW Vienna rectifier is built based on DSP TMS320F2808 development board.