基于状态转移矩阵的小水电机组发电系统可靠性评估

Reliability Evaluation of SHP Generation System Based on State Transition Matrix

作为我国重要的电力资源,小水电机组大规模并网运行给发电系统乃至整个电网可靠性与安全运行带来新的挑战。由于小水电数量众多,容量不等,采用现有递推公式建立停运容量模型来进行小水电机组发电系统可靠性评估时步骤繁琐,中间数据多,工作量大,对此提出了一种基于状态转移矩阵的小水电发电系统可靠性算法,用状态空间图表示小水电机组停运容量模型,基于状态空间算法直接计算小水电机组各个停运容量状态的确切概率,由转移率矩阵适当变换求取增量频率,用分块矩阵组合表示小水电机组停运容量模型和负荷容量模型的组合,合并相同容量状态,增加等步长而未出现的容量状态,即得小水电发电系统的裕度容量模型,进而计算累积概率、累积频率等可靠性指标。算例分析验证了此算法的可行性,可在实际操作中推广应用。

As an important role in the power resource of China,the collection of large-scale small hydropower(SHP)connected power grid has issued new challenges to the reliability and security of operation.Because of the large number and numerous capacities of SHP,the traditional outage capacity model by the recursive formula has complicated steps,mass intermediate data and heavy workload for the reliability evaluation.In this paper,a reliability algorithm of SHP generation system based the state transition matrix is proposed.The outage capacity model of SHP group is built by the state space diagram.The exact state probability is calculated by the state space method.The incremental frequency is calculated by the transformed transfer rate matrix.The outage capacity model and load capacity model are combined by the transfer rate matrix.And then the margin capacity model is completed by combining the states with the same margin and adding the states that do not appear by the given step size.Then,the cumulative probability,cumulative frequency and other reliability indices are calculated.Numerical examples demonstrate the correctness of the proposed method,which can be promoted in practice.