基于价格响应函数的超大电网分解协调优化方法

Decomposed Optimization Method over Large-scale Power System Based on Price Response Function

针对超大电网安全经济调度优化问题,提出了一种基于价格响应函数的新型分解协调模型与方法。该方法以省级电网为基本优化单元,将全网优化问题分解为上级主问题和省级子问题。在上级主问题中,只保留联络线节点,化简省级电网,并通过跨省联络线互联生成全局虚拟网络;根据省级子问题的优化结果生成动态价格响应函数,优化决策跨省联络线功率。省级子问题在给定联络线功率下优化机组出力(机组组合方式已确定),并将不同时段的发电负荷以及对应的边际价格信息提供给上级主问题。该方法充分挖掘并利用了每一次省级子问题的优化结果中所隐含的价格信息,从而避免了传统Lagrange方法反馈单一价格信号导致的振荡问题,具有较好的鲁棒性和工程实用的优化精度。基于IEEE RTS和"三华"电网的计算充分表明了该方法的有效性。

A novel decomposed optimization method based on price response function is proposed for solving security constrained economic dispatch problem over large-scale power systems. In this method, provincial power systems are taken as basic optimization units, and the global optimization problem is decomposed into an upper-level master problem and provincial sub-problems. In the master problem, network reduction technique is imposed, and the dynamic price response function is trained based on the results of the sub-problems in order to optimize the power flow of inter-province tie-lines. In the sub- problems, power output of generating units is optimized with fixed tie-line export, with marginal pricing information corresponding to power loads of different time periods calculated and submitted to the upper-level. The proposed method fully exploits and utilizes the implicit pricing information in the sub-problem results of each iteration, thereby avoiding the oscillation from which the conventional method of Lagrange relaxation suffers much because of the monotony of pricing signal. Hence, the method is able to converge quickly in a few steps with good robustness and sufficient accuracy from the engineering point of view. Computational results of IEEE RTS and a large-scale real power system are presented to verify the effectiveness of the method.