风速波动导致的风电机组有功功率波动是引发风电电压问题的根源,需要针对不同风况研究对应的电压控制策略。极端风况下风电场群运行状态变化巨大,而本地无功连续调节设备的闭环控制能力有限,故提出一种基于超短期风功率预测,能够分别对极端风况发生前、后的风电场群及附近地区电网电压进行预防控制和校正控制的电压协调控制策略;其优化算法能够将此非线性混合整数规划问题,通过考虑有功变化的无功-电压灵敏度方法,解耦成为一个包含混合整数线性规划和非线性代数方程组求解子问题的迭代过程。通过算例证明了传统闭环控制方法的局限性,以及本文策略在电压控制和均衡风电场内馈线电压方面的优越性,为解决极端风况的高电压脱网问题提供一种有效方法。
It's necessary to study corresponding voltage control strategies for different wind conditions because the active power fluctuation caused by wind speed fluctuation is the fundamental reason of voltage problem. Considering tremendous changes of wind farm clusters' running status under extreme wind conditions and limited closed-loop control capability of local reactive power continuously adjustable equipment, a corresponding voltage control strategy was proposed, which could provide preventive voltage control and corrective voltage control for conditions before/after extreme wind speed based on ultra-short-term wind power prediction. Its optimization algorithm could decouple the MINLP (mixed-integer nonlinear programming) problem through reactive power-voltage sensitivity method with considering active power change and turned it into an iteration containing a M/LP (mixed-integer linear programming) problem and some nonlinear algebraic equations. By comparing the examples, the limitation of the traditional closed-loop control method and the superiority in voltage control and wind farm's internal feeder voltage balance through the proposed control strategy can be verified, which can provide an effective method for solving the high voltage off-grid accident under extreme wind conditions.