Control of Three-Phase PWM Rectifier under Unbalanced Input Voltage Conditions without Sequential Component Extraction

Many methods for control of three-phase boost-type PWM rectifier under unbalanced input voltage conditions have been presented in the last two decades. Among these methods, the input-output-power-control (IOPC) method seems the most desirable one offering ripple-free dc bus voltage, low-distortion input currents and average unity power factor on the grid side. Most of the IOPC schemes adopt rotating frame and sequential component extraction of the input voltages, rectifier pole voltages and/or input currents are almost unavoidable. Anyway, this paper presents a novel IOPC method which can regulate the instantaneous active/reactive powers in stationary frame. Compared with the conventional methods, the most important advantage of the proposed algorithm is the complete elimination of the sequential component extraction, which means much reduced time delay can be expected in the control system. Meanwhile, grid voltage phase detection and rotating transformation are also nullified. Experimental results on a 30 kVA PWM rectifier prototype show validity of the proposed method.