New direct power control of three-phase PWM boost rectifiers under distorted and imbalanced line voltage conditions

The three-phase PWM boost rectifier is an interesting solution thanks to advantages as: bi-directional power flow, low harmonic distortion of line current, regulation of input power factor to unity, adjustment and stabilization of DC-link voltage. This paper proposes a new direct power control for this kind of converter using space vector modulation (DPC-SVM). The active and reactive power is used as the pulse width modulated (PWM) control variables instead of the three-phase line currents ever used. Moreover, line voltage sensors are replaced by virtual flux (VF) estimator. The theoretical principle of this method and the synthesis of the active and reactive power controllers are discussed. The steady state operation, dynamic results and behaviour under distorted and imbalanced line voltage conditions that illustrate the performance of the DRC-SVM are presented. It is shown that the proposed method exhibits several features as: simple tuning procedure of PI power controllers, good dynamic response, constant switching frequency and sinusoidal line current when supply voltage is non ideal. Simulation and experimental results have proven excellent performances and verify the validity of the proposed system.