考虑电压稳定裕度约束的点估计随机最优无功调度方法

Stochastic Optimal Reactive Power Dispatch Method Based on Point Estimation Considering Voltage Stability Margins

传统无功优化方法通常采用确定型的模型,但新能源大量接入以后,节点注入功率并不确定,针对其随机性,提出一种考虑电压稳定裕度约束的随机无功优化方法,使用基于点估计的随机潮流方法将机会约束转换为确定型约束,并采用带共轭梯度算子的改进遗传算法对优化问题进行求解。数值计算的结果表明该方法可以降低电压的越限风险。相比于确定型方法,使用该方法后网损优化结果略有增加,但同时电压稳定裕度得到了较大的提升。

Conventional optimal reactive power dispatch approaches operate mostly in deterministic form where the power injections are known and fixed. However, in practice, power injections, especially from intermittent renewable sources, and demands are uncertain. Therefore, this paper develops a voltage stability margin constrained stochastic optimal reactive power dispatch( VC-SORPD) method. The chance constrains have been transferred into the deterministic constraints by the stochastic optimal reactive power method based on the point estimation. Then the programming is solved through the genetic algorithm with the improved conjugate gradient operator. Simulation results on several cases demonstrate that the proposed method is able to prevent under and over-compensation and increase the load margin at a cost of a small but acceptable increase of active power losses.