Improved active power dynamic response of voltage‐controlled doubly fed induction generator

Abstract

Abstract The voltage‐controlled doubly fed induction generator (VC‐DFIG) is widely studied because of its self‐synchronous control characteristics and its ability to actively support the grid voltage and frequency. However, the VC‐DFIG is a multi‐loop and cascade‐controlled system, and the bandwidth design of each control loop is difficult. When the power instruction and grid frequency disturbances occur, the improper bandwidth designs will cause severe oscillation and overshoot. In this study, the Thevenin equivalent voltage model of DFIG is derived, combined with the characteristics of voltage control, and the control structure of VC‐DFIG is constructed. On this basis, a small signal model of active power dynamic response is established, which includes the characteristics of the voltage control loop and active power loop. For the parameter robustness and dynamic response of VC‐DFIG, the frequency damping control strategy and the lead‐lag correction control strategy are proposed. Finally, the enhanced VC‐DFIG technology was realised through the 2.0 MW DFIG experimental platform, and the effectiveness of the two proposed control strategies were verified.

Keywords

• asynchronous generators
• voltage control
• damping
• machine control
• power grids
• dynamic response