Reactive Power and Voltage Control in VSC-HVDC Connected Wind Farms Considering Stochastic Wind Power

Wind power changes instantaneously during the control interval of automatic voltage control (AVC) system. To enhance the control effect in voltage-source-converter-based high-voltage direct-current (VSC-HVDC) systems with wind farms integration, this paper proposes a reactive power and voltage control scheme considering the stochastic deviation from baseline wind power. The uncertainties of wind power during the control interval are characterized by state-based generated scenarios. Through a scenario-based optimization, the reduced scenarios are used to optimize expected network losses while the extreme scenarios ensure the voltage security. Case studies based on Monte Carlo simulation show the proposed method decreases the voltage bounds violations with acceptable network losses. In addition, the balance between economy and robustness can be adjusted by parameters in the control scheme.