基于随机响应面法的配电网故障恢复全时段不确定性优化方法

A Full Period Stochastic Optimization Method for Fault Recovery in Distribution Networks Based on Stochastic Response Surface Method

配电网故障恢复是电网安全经济运行的重要保障,为消除故障恢复过程中分布式电源不确定性对电网运行的风险,该文计及全时段不确定性影响,基于随机响应面法构建配电网故障恢复的混合整数二阶锥规划随机优化模型;为准确评估储能系统的运行风险,对各时段储能荷电状态的随机性进行概率等价处理,并基于Hermite混沌多项式的特征系数构建配电网安全运行的机会约束凸函数,确保解的全局唯一性;为降低优化模型的复杂度,在保证随机过程拟合精度的前提下,提出简化的随机潮流约束,以减少二阶锥松弛约束的使用。最后,通过蒙特卡洛仿真发现,所提随机优化模型能准确描述随机响应的概率特征,在满足安全运行的机会约束下,可最大化减少停电损失。

The fault recovery in distribution networks is an important guarantee for the safe and economic operation of the power grid.To eliminate the risk of distributed power generation uncertainty on grid operation during fault recovery process,this paper constructs the mixed integer second-order cone programming(MISOCP)stochastic optimization model for distribution network fault recovery based on the stochastic response surface method(SRSM),taking into account the influence of the uncertainty in the entire periods.To accurately evaluate the operational risk of the energy storage system(ESS),a probability equivalence scheme is applied to the randomness of the state of charge of ESS at each time period.Based on the characteristic coefficients of Hermite chaotic polynomials,the convex function of opportunity constraints for distribution network fault recovery is constructed to ensure the global uniqueness of the solution.To reduce the complexity of the optimization model while maintaining the accuracy of the stochastic process fitting,a simplified probabilistic load flow model is proposed to reduce the number of items in the second-order cone relaxation constraint.Finally,the Monte Carlo simulation is employed to compare and validate the proposed stochastic optimization model in this paper.The results demonstrate that the proposed method accurately describes the probability characteristics of random response and maximizes the allocation of sources to minimize outage losses,while adhering to the opportunity constraints of safe operation.