Application of D-Q Axis Transformation Control Strategy for Three-phase AC/DC Converter

In this paper, a new control strategy for three-phase AC/DC converter has been proposed. Basically, the proposed converter adopts three-phase full-bridge circuit and has several advantages such as sinusoidal input current, unity power factor and energy regeneration. For the requirement of control loop, three phase AC signals are transformed to DC d-q signals by using the D-Q axis transformation so that the converter has faster dynamic response. The general solution of switching duty ratio is obtained by using the state space averaging technique. Based on the solution, a dead-band control modulation is implemented to drive the proposed converter. The effectiveness of the control can reduce 1/3 times of switching number and switching losses successfully. Consequently, the efficiency and voltage utilization of the converter can be increased. Both TI DSP TMS320F28335 and VisSim software are employed to achieve digital control successfully. The advantages of the converter include size reduction and easily adjusting the control parameters. Finally, some experimental results are presented to verify the feasibility of the proposed control strategy.