Wind turbine multiphase operational trajectory in an all‐DC wind generation system

An operational trajectory and a control scheme for wind turbine generators (WTGs) in an all‐DC wind system is proposed in this study. The wind turbine includes a multiphase hybrid generator (HG) and a passive rectification stage. The WTG output is sent to an off‐shore substation using a medium‐voltage DC (MVDC) collector grid. The off‐shore substation is connected to the terrestrial grid using a high‐voltage DC (HVDC) transmission grid. The multiphase HG employs a two‐rotor topology and facilitates an active control over the wind turbine power and voltage. The proposed control scheme allows for a variable MVDC grid voltage while maintaining a wind turbine desired power under maximum power point tracking. The wind turbine trajectory is a path that wind turbine operates on as the wind velocity varies, and it is defined by HG control current, MVDC grid voltage and wind turbine power. To present the effectiveness of the proposed control and verifying the analytical model of wind turbine trajectory, a simulation platform is developed and results are presented.