Rotor power factor adjustable direct torque control of doubly-fed induction generators for wind power generation

In this paper, direct torque control (DTC) technology of doubly-fed induction generator (DFIG) is analyzed in detail and applied to variable speed constant frequency wind power generation system. A rotor power factor adjustable DTC with maximum wind power tracking is discussed and rotor voltage vectors are obtained based on the look-up table. Based on the stochastic wind which is generated by the Turbsim software, theoretical analysis of the control strategy is done and the corresponding scheme is given. The simulations in both sub-synchronous and super-synchronous operation modes are carried out to examine the performance, where S-function is adopted for the realization of the selection of sectors and voltage vectors. It is shown that the simulation results agree with the theoretical analysis well.