Direct slip angle control for rotor side converter of standalone DFIG‐DC system

Abstract

This paper presents a direct slip angle control (DSAC) for rotor side power converter of standalone doubly-fed induction generator (DFIG) DC systems. The conventional direct torque control (DTC) for the rotor side converter (RSC) of the standalone DFIG-DC system is also introduced to evaluate the proposed DSAC compared to the conventional DTC method. In this regard, the proposed DSAC method is mathematically analyzed. Then, three states including output DC voltage change, wind speed change, and load change are simulated and performed for both the proposed DSAC and conventional DTC methods. Various simulations and experiments substantiate that the electromagnetic torque ripple, current harmonics, and the output DC voltage dip, caused by the sudden load-change, are reduced in the proposed DSAC method compared to the conventional DTC method. Besides, the parameter dependency is reduced in the proposed DSAC method since the stator voltage and current sensors are removed.