Virtual flux based direct power control of three-phase PWM rectifiers

In this paper direct power control (DPC) of three-phase PWM rectifiers without line voltage sensors is presented. The new system is based on virtual flux (VF) estimation. The theoretical principle of this method is discussed. The steady state and dynamic behaviour of VF-DPC are presented that illustrate the operation and performance of the proposed system compared to a conventional DPC method. Both strategies are also investigated under unbalance and pre-distorted grid. It is shown that VF-DPC exhibits several advantages, particularly providing sinusoidal line current when supply voltage is not ideal. Some test results show the excellent performance of the proposed system.