配电自动化条件下配电系统供电可靠性评估

Reliability Evaluation for Distribution Systems with Automation

针对配电自动化新技术的应用提供了提高供电可靠性的情况,建立了面向供电可靠性分析的配电系统简化模型。该模型将复杂配电网分解为许多最小配电区域,分别计算出其等效故障率和等效平均故障修复时间,再以最小配电区域为单位设置故障并分析其后果,还计及了母线、开关故障和检修的影响,并且在分析故障和检修影响时考虑了系统的电气极限容量,在确保系统安全的条件下借助配电自动化,采取以甩负荷最小为目标的网络重构,最终得出各个负荷点以及系统的供电可靠性指标。实例分析表明,提出的方法可行并显著提高了分析效率,且能够反映配电自动化对配电系统供电可靠性的影响。

A graph theory based simplified model for distribution reliability evaluation is set up. The switches, feeder ends and feeder taps are defined as vertexes. The feeder sections between each two vertexes are defined as edges. A minimum distribution region is defined as the sub-graph surrounded by switches and feeder ends and with only feeder taps inside the sub-graph. A complicated distribution system is divided into many minimum distribution regions. Equivalent parameters of fault probability and averaged reparation time are calculated for each minimum distribution region. Faults are set on each minimum distribution regions and the influences are analyzed for each setting. Faults on buses and switches and maintenances are included in the evaluation. The electrical limitations of apparatus are also considered. Based on distribution automation, network reconfiguration approaches with minimum shedding load are adopted in calculating the reliability to ensure thesafety of operation. To further improve the efficiency of evaluation, customers are divided into classes and the influences of each setting are analyzed according to the characteristics of the corresponding class. Flow chart of reliability evaluation for distribution systems with distribution automation is described. An example is given showing the feasibility of the proposed method. It is also shown that the efficiency of evaluation is remarkably improved and the influence of distribution automation on reliability can be well evaluated.