改善接入地区电压稳定性的风电场无功控制策略

针对大规模风电场接入电网带来的电压无功问题，提出一种改善接入地区电压稳定性的变速恒频风电场无功控制策略，在系统发生扰动时，以接入点为电压控制点，扰动前的稳态电压为控制目标，动态调节风电场输出无功功率，维持接入点电压水平。实际应用时，该策略利用系统部分雅可比矩阵推导风电场的电压无功灵敏度信息，并根据风电场的无功输出能力计算风电场无功调整量，同时通过设置控制死区和延时，避免了风电机组的频繁调控。仿真算例表明，采用所提策略能够充分发挥变速恒频电机风电场的快速无功调节能力，有效抑制风速扰动、负荷变化等因素引起的电压波动，维持接入地区电网的电压稳定性。

Strategy for Reactive Power Control of Wind Farm for Improving Voltage Stability in Wind Power Integrated Region

A strategy for reactive power control of variable-speed constant-frequency (VSCF) generator based wind farm for improving voltage stability in wind power integrated region is proposed to solve voltage and reactive power issue in power grid with large-scale wind farm integrated. If system disturbances make voltage fluctuating, the point of interconnection (POI) is selected as a voltage control point and steady-state voltage without disturbances is selected as control object. Then reactive power output of wind farm is regulated dynamically to maintain voltage level at POI. In specific implementation, the voltage/reactive power sensitivities of wind farm which is derived from partial Jacobian matrix are used for calculating reactive power output adjustments of wind farm according to reactive power output volume of wind farm . Meanwhile, dead band of voltage and time-delay are set to avoid wind generator controlling frequently. Example shows that the proposed strategy can make full use of reactive power regulating ability of VSCF generator based wind farm to restrain voltage fluctuation caused by disturbances such as wind speed or load variation and maintain voltage stability in interconnected regional power grid.