Modeling and Response Characterization of Wind Turbines under Frequency-Voltage Coupled Disturbance Conditions

With the growing share of renewable energy and the rapid deployment of HVDC, the new power system increasingly exhibits characteristics of high power electronics integration. In this context, the frequency-voltage coupling characteristics of the system during disturbances become increasingly prominent, making the traditional approach of addressing frequency and voltage issues separately less effective. The high/low voltage ride-through (H/LVRT) and frequency regulation (FR) characteristics of renewable energy units are key factors influencing the system's frequency-voltage coupling behavior. This paper initially establishes a generalized electromagnetic transient model for wind turbine generators (WTGs), incorporating high and low-voltage ride-through control along with frequency regulation control. Subsequently, by analyzing the active and reactive responses of WTGs during coupled system frequency-voltage disturbances, the influence of wind turbines on system frequency-voltage under typical control strategies is clarified. Finally, a test system is set up on the MATLAB/Simulink simulation platform to validate the accuracy of the proposed generalized model for WTGs and their frequency-voltage coupled response characteristics. The simulation results indicate that the coupling between the active and reactive power of the WTG is most pronounced during simultaneous frequency and voltage dips, which can potentially cause a further decline in system frequency.