基于无迹变换的含大规模风电场电力系统概率最优潮流计算

摘要

A computation method for probabilistic optimal power flow(POPF)for power systems with large-scale wind farms based on unscented transformation (UT) technique is proposed.UT technique is employed to transform the POPF problem into the deterministic OPF problem with a few samples to be solved with the interior point method.The randomness of the wind farms”output power and the uncertainty of the bus load power are considered,the calculation accuracy of the probability characteristic parameters of the variables in the model of POPF using this method under different wind power capacities in power systems is discussed.The numerical results of IEEE 30-bus,57-bus,118-bus standard systems and a real system S-1047 indicate that,compared with Monte Carlo (MC) method,the proposed approach for POPF based on UT technique can remarkably reduce the computing time while keeping a high accuracy.It is easy to implement and facilitates handling of the correlation of the random variables,while providing a powerful tool for the solution and practical application of the POPF problem.%提出了一种基于无迹变换(UT)技术求解大规模风电场并网的电力系统概率最优潮流(POPF)的计算方法。利用UT技术将 POPF 问题转化为少量样本点的确定性最优潮流问题，然后采用现代内点法加以求解。考虑了风电场出力的随机性和节点负荷功率的不确定性，讨论了不同风电接入水平下利用该方法计算 POPF 模型中变量的概率特征参数的计算精度。IEEE 30节点、IEEE 57节点、IEEE 118节点标准系统和一个实际系统 S-1047的计算结果表明，与蒙特卡洛方法相比，基于 UT技术的POPF计算方法在保持误差很小的同时，计算效率可提高数十倍，且容易实现、易于处理随机变量相关性，为POPF问题的有效求解和应用提供了工具。