An Adaptive Droop Coefficient Based Voltage Control Approach for Wind Power Plants through Enhanced Reactive Power Support

To maximize the reactive power support from a wind power plant (WPP) and maintain the power factor (PF) at the point of interconnection (POI) within acceptable limits, an adaptive droop coefficient-based WPP controller is proposed in this paper. The controller consists of a central WPP controller and a local wind turbine generator (WTG) controller. An integrated power factor controller enables the central WPP controller to regulate the power factor at the POI under normal operation. An updated droop coefficient model considering the depth of voltage deviations and the range of reactive power capability enables the controller to push the WTG more towards its maximum reactive power limit. For accurate estimation of the maximum reactive power capability, a comprehensive model considering a wide range of limiting factors has been used. To ensure faster and robust operation, both the central WPP controller and local WTG controller are operated in the voltage control mode. Additional reactive power is exported from the grid side converter (GSC) through a developed GSC controller. The effectiveness of the proposed controller is validated through case studies in MATLAB/Simulink environment.