中文摘要：

由于电力系统运行中存在不确定性，因此在机组组合中有必要考虑机组投运风险水平的限制．但机组投运风险水平与机组强迫停运容量呈离散型的分布关系，因而难以与拉格朗日松弛法的机组组合算法有机结合．就这一问题，在前人研究的基础上，对系统投运风险曲线的两种拟合形式，即高斯函数和指数函数，进行分析和研究，发现前者精度较后者明显提高．在此基础上，将投运风险度约束以解析表达的方式引入机组组合的拉格朗日松弛法中，有机一体的完成了概率备用约束的机组组合问题，实现真正意义上的优化．

英文摘要：

of the existing uncertainty in power system operation, it is necessary to consider the risk of unit commitment. However, the relation between unit commitment risk and unit forced outage capacity is discrete, which leads to a difficult combination with the l.agrangian relaxation method of unit commitment. Two kinds of curve fitting forms of the unit commitment risk are analysed, which are the Gauss function fitting and exponential function fitting. The research shows the results of Gauss function fitting is more accurate than that of the exponential function fitting. By introducing the analytic expressed unit conmaitrnent risk constraints into the unit conmiitment Lagrangian relaxation method, the probability reserve constrained unit conmaitment problem can be achieved and optimized.