Coordinated voltage control scheme for VSC‐HVDC connected wind power plants

This study proposes a coordinated voltage control scheme based on model predictive control for voltage source converter (VSC)‐based high voltage direct current connected wind power plants. In the proposed scheme, voltage regulation capabilities of VSC and wind turbine generators (WTGs) are fully utilised and optimally coordinated. Two control modes, namely the operation optimisation mode and corrective mode, are designed to coordinate voltage control and economic operation of the system. In the first mode, the control objective includes the bus voltages, power losses and dynamic Var reserves of WTGs. Only the terminal voltages of WTGs are considered in the second mode. The predictive model of the system including VSC and WTGs is developed firstly. The calculation of sensitivity coefficients is done by an analytical method to improve the computational efficiency. Simulation results are presented to demonstrate the effectiveness of the proposed controller and the control performance is compared with conventional optimal control and loss minimisation control. Besides, the robustness of the proposed controller to communication time delay and measurement errors is investigated in the last.