Frequency Domain Modeling and Analysis of DFIG Considering Power Control Loop

The broad frequency band oscillation accident of the power system caused by the integration of wind power generation seriously threatens the safety and stability of the power system. Frequency domain modeling and analysis is an important method to study system stability. In order to simplify the system complexity, the derivation of the doubly fed induction generator (DFIG) admittance model generally only considering the impact of the current control loop. But when the voltage disturbance occurs at the point of common coupling (PCC), the power control loop will inevitably introduce the power fluctuation into the current control loop, which will affect the admittance characteristics. This paper derives DFIG admittance models under the dq axis that consider both the current control loop and the power control loop of the rotor side converter (RSC). Moreover, comparative analysis of three types of admittance model is carried out, which is based on actual parameters. The results show that it is necessary to consider the controller in modeling and analysis, and the power control loop has a great influence on the DFIG admittance matrix.