The Direct Power Control with Constant Switching Frequency Based on a Triangular Waveform Comparator of Doubly Fed Induction Generator

The traditional direct power control of doubly fed induction generator (DFIG) is based on the hysteresis comparator. However, the common problem for this strategy is that the switching frequency is non-constant. In order to solve the problem, based on the dynamic model analysis of DFIG, the hysteresis comparator is replaced by a triangular waveform comparator to generate the active power state. This paper presents an improved constant switching frequency of direct power control strategy. In MATLAB/SINIULINK, simulation results for a 15KW DFIG system demonstrate constant switching frequency, excellent dynamic performance, and low power ripple in tracking active power, reactive power and speed of the process.