STUDY ON SLIDING MODE VIRTUAL FLUX ORIENTED CONTROL FOR THREE PHASE PWM RECTIFIERS
This paper presents the design of the sliding mode control technique for three phase boost type PWM rectifier based on virtual flux vector orientation. A sliding mode control algorithm on synchronous rotating reference frame is employed for each current and dc voltage control loops. The Lyapunov direct method is used to ensure the reaching and sustaining of the sliding mode. The logic control signals (Sa, Sb, Sc) are calculated by using the space vector modulation (SVM) technique. To alleviate chattering phenomenon without compromising system robustness, a tangent hyperbolic function is used in the dc voltage loop instead of a conventionally sign function. The proposed sliding mode control system has been simulated using MATLAB SIMULINK Software and compared with traditional PI controller. The comparison shows that the sliding mode control scheme is more robust against load changes and power supply variations. Furthermore, it confers better dynamic performance.