Influence of circuit and control parameters on the stability of DC wind turbine generators

With the fast development of wind energy, the stability of DC collection system for large-scale offshore wind farm has been an increasing concern. DC wind turbine is an essential component of offshore wind farm in DC collection system. However, DC wind turbines are based on power electronic devices, and the interaction between different power electronic devices may cause complex frequency oscillations, which seriously threaten the safety and stability of the power system. The paper mainly analyzes the influence of circuit parameter and control parameters on the stability of DC wind turbines. The impedance models of the AC/DC converter and DC/DC converter of the DC wind turbine were established, and the system circuit was built in MATLAB/Simulink. The feasibility of the impedance model was verified through frequency sweep method. The Nyquist curves of impedance ratio of AC/DC converter to DC/DC converter were drawn based on theoretical models. The influence of circuit parameters and control parameters on the stability of DC wind turbines is analyzed infrequency domain and time domain respectively.