A Novel DC Capacitor Inertia Control With Channel Decoupling for DFIG Based on Robustness to Frequency Fluctuation

ABSTRACT The existing DC capacitor inertia control (DCIC) used in the grid side converter (GSC) of doubly fed induction generator (DFIG) faces many issues such as a significant impact on DC bus voltage (DCBV) from grid frequency fluctuations, coupling of control parameter channels, and poor control stability. To tackle the above issues, this paper designs a novel DCIC method. This DCIC method removes the damping compensation branch in the phase control channel of the converter voltage modulation wave and adds a frequency‐resistant decoupling element (FRDE) to this branch. This effectively reduces the impact of grid frequency fluctuations on maintaining a constant DCBV in the GSC and enables the GSC under the designed control method to equivalently emulate the operational characteristics of a synchronous generator with damping. A thorough analysis of the disturbance rejection performance of the novel DCIC method in various aspects is conducted by establishing and utilizing a small‐signal model of the control system, combined with Bode plots. Finally, a comprehensive simulation model was established on the MATLAB/Simulink platform. Comparative studies were conducted between the conventional DCIC method and the designed method, validating its correctness and performance accuracy.