Performance analysis of three-phase PWM rectifier using direct power control

This paper presents a direct power control (DPC) based on grid virtual-flux for controlling the operation of three-phase, three-wire pulse-width modulation (PWM) bidirectional rectifier. Virtual-flux of main supply voltage is used to estimate the instantaneous active and reactive power of the PWM rectifier. Theoretical background of the DPC scheme utilizing virtual-flux of supply voltage is provided, giving a basic understanding the operation of PWM rectifier as a power conditioner. Some results of computer simulation and hardware implementation are given for studying and analyzing the operation and performances of the rectifier under the steady-state and transient conditions. The results have shown that DPC with virtual-flux implementation exhibited several advantages as compared to the conventional DPC scheme such as low total harmonic distortion of input currents, almost unity power factor operation and good dynamic response.