Sensorless control of PWM rectifier by distorted supply voltage

A sensorless control strategy for three phase PWM power supply rectifiers, a "phase tracking" concept, was proposed on last PESC'03. This method proved to be robust to system parameters changes and provided line voltage estimation for line current control. Discussion after the PESC'03 presentation left concerns with respect to the control quality during line voltage fluctuations and under nonsymmetric line conditions. This paper reports the behaviour of the proposed "phase tracking" control method under distorted supply voltage. The following voltage distortions are tested: voltage unbalance, over-voltage and under-voltage. The control was performed on a rapid prototype system for power electronics control. Experimental results of the test are presented.