Analysis on Interaction of Wind Farms with UHVDC under Commutation Failure

To achieve the strategic goals of "carbon peak" and "carbon neutrality," large-scale clean energy, primarily from wind power, is transmitted via ultra-high voltage direct current (UHVDC) systems, leading to significant changes in the power grid structure. A DC phase-change fault can cause transient overvoltage at the DC sending end, a critical issue that needs addressing. This paper investigates the complex interactions between the wind power base and the UHVDC transmission system during fault conditions. An electromagnetic transient model of the wind power base connected to the UHVDC system is developed using PSCAD/EMTDC software. The study analyzes the impacts of the wind power base on the UHVDC transmission system and vice versa while exploring the effects of varying wind power penetration rates, fault ride-through capabilities of wind turbines, and turbine faults. The system's response characteristics under different wind power penetration levels, fault ride-through parameters, and DC control settings are also discussed.