Online Inductance Identification of a PWM Rectifier Under Unbalanced and Distorted Grid Voltages

Direct power control (DPC) works well under ideal grid voltage conditions with accurate parameters. However, under unbalanced and distorted network conditions, significant power ripples and current harmonics arise in conventional DPC if no special measures are taken. Furthermore, the system performance further deteriorates if the inductance value differs from the actual value. To cope with the problems above, this article proposes an online inductance identification method for the DPC of a PWM rectifier under unbalanced and distorted network conditions. It is shown that the proposed method can guarantee sinusoidal characteristics of the grid current and reduce power ripples under unbalanced and distorted network conditions when the identification algorithm is enabled. The presented simulated and experimental results confirm the effectiveness of the proposed method.