A model-based PDPC method for control of BDFRG under unbalanced grid voltage condition using power compensation strategy

Abstract

Brushless doubly fed reluctance generator (BDFRG) has been recently suggested as a wind generator. Different control methods are presented in literature for the BDFRG, but there is a gap on control under unbalanced grid voltage condition (UGVC). This paper presents a predictive direct power control (PDPC) method for the BDFRG under UGVC. The proposed PDPC method is based on power compensation strategy, and aims to balance the BDFRG current (strategy I), and to remove the electrical torque pulsation (strategy II). The control objectives are defined using the BDFRG positive sequence (PS) and negative sequence (NS) equations. Then, the active power and reactive power variations are predicted to compute the required voltage for the BDFRG control winding. Finally, the BDFRG is controlled by applying the calculated voltage to the control winding. Simulink toolbox of MATLAB software is used to simulate the system model. Both the proposed PDPC method (with strategies I & II) and the original PDPC method (without a compensation strategy) are applied to control of the BDFRG under UGVC, and the results are compared. The results show the good performance of the proposed PDPC method.