A Novel Current Regulator for DFIG Wind Turbines with Enhanced Performance under Unbalanced Supply Voltage Condition

This paper proposes a new vector-based hysteresis current regulator (VBHCR) in the rotor-side converter of DFIG to enhance the control performance under unbalanced supply voltage condition. The "Gamma-form" is used for the equivalent circuit of the machine to reduce the modeling complexity. This is followed by presenting the principle and practical implementation of the proposed VBHCR in the DFIG application. Compared to the widely-used PI current regulators, the proposed VBHCR exhibits very fast transient response with a simple control structure. Simulation results, obtained using Matlab/Simulink for a 1.5 MW DFIG, show the validity of the proposed control scheme under normal operation as well as its superiorities under unbalanced supply voltage condition.