电网规划中最小切负荷费用计算方法

Calculating Method of Minimum Load-Shedding Cost in Transmission Network Planning

电力市场环境下的电网规划需要综合考虑电网的投资费用、运行费用和切负荷费用,所以有必要计算各规划方案的最小切负荷费用。通过建立以切负荷费用最小为目标函数的数学模型,提出了逐步经济切负荷法。该方法是一个逐步消除系统过负荷的迭代过程。每一次迭代中引入经济有效度指标来综合考虑候选节点的切负荷有效度和单位切负荷费用,并以此确定一个切负荷最佳节点以及该节点的切负荷量。当系统再无过负荷时,就终止迭代。此时,所有切负荷节点上的切负荷费用之和即为系统最小切负荷费用。算例证明了该方法的有效性和可操作性,与电力市场下电网的实际运行情形相吻合。

The transmission network planning under power market enviroment should consider the investment, operating and load-shedding cost synthetically, so it is necessary to calculate the minimum load- shedding cost of transmission alternatives. In this paper a load-shedding mathematical model is established whose objective is to minimize the load-shedding cost, and then a calculating method of gradual economic load-shedding is presented to solve the model. The method is a iterative process of eliminating system overloads gradually. In each iteration, an economic efficiency index is introduced to take into account both the load-shedding efficiency and unit load-shedding cost for each bus, and then the optimal load-shedding bus and its load-shedding quantity is chosen. When all system overloads are cleared up,the iteration is stopped. Thus the sum of load-shedding cost in all load-shedding buses is determined as the minimum load-shedding cost of the system. A calculating example demonstrates that the method is efficient, operable and coincides well with the actual situation under the power market.