A new method to coordinate the PI controllers' parameters of doubly-fed induction generator

The PI controllers of doubly-fed induction generator (DFIG) include three pairs of parameters, which have an important influence on the system dynamics. The existing coordinated method [1] gives the approximate scope of the PI parameters; however, random combination of the three group of parameters may result in a critical stable state. By recognizing this, this paper pushes forward the work in [1] and proposes a new method to coordinate the PI controller's parameters of DFIG, which considering the interaction between three group of parameters and ensuring the DFIG system operated in a stable state. The proposed method includes following steps. firstly, it determines the optimal PI parameters for the outer voltage loop of GCC by neglecting the influence of the other two group of PI parameters; and then, determine the optimal PI parameters for inner current loop of GCC, considering the influence from the outer voltage loop PI parameters of GCC, and finally, determine the optimal PI parameters for current loop of RCC, considering the influence from the two group of parameters above and the optimal condition, which is find a group of parameters to make the maximal eigenvalue to a minimum. Finally, this paper presents the simulation results with a typical DFIG system based on RTDS, and the simulation results show that the PI parameters determined by the proposed method can ensure the DFIG system having a good performance.