An OPF-Based Strategy for Co-Optimization of Dynamic Voltage Support and Wind Power Curtailment During Voltage Sags
Abstract
A novel optimal power flow (OPF) strategy is developed to simultaneously optimize the dynamic voltage support (DVS) capability and active power output curtailment of wind generators. It is challenging to satisfy both voltage and frequency constraints of a power system during a voltage drop in conventional DVS approaches without steady-state reactive power support. In order to address this point, the proposed method can optimize the DVS capability of the wind model depending on the system voltage and frequency constraints. The active power output of the wind models is curtailed to secure steady-state reactive power production when the DVS is not sufficient. The developed strategy is validated using the Western System Coordinating Council (WSCC) nine-bus and IEEE 39-bus test systems with wind generation models. Numerical results indicate that the proposed method effectively adjusts the DVS capability of wind sources to satisfy voltage constraints. However, excessive enhancement of DVS should be avoided to limit frequency deviation. As a consequence, the DVS capability is reduced when the frequency constraint is considered. The simulation results indicate that the OPF approach can satisfy both voltage and frequency constraints by jointly optimizing the DVS capability and wind power curtailment level.