提出一种考虑大停电风险的多阶段电网扩展规划方法,并定义了一种幂律尾风险指标,通过评估停电规模尾分布的变化趋势来衡量规划方案的大停电风险。为了获取规划方案对应的停电统计数据,基于自组织临界理论构建了适用于多阶段电网扩展规划的OPA模型。该模型在慢动态中考虑了相邻规划阶段之间的耦合关系,在快动态中考虑了隐性故障,分别反映了长时间尺度内的电网扩展规划行为和短时间尺度内的连锁故障行为对系统全局动态特性的影响。另外,慢动态过程取消了基于平均效应的长期演化行为;快动态过程使用蒙特卡洛方法以获取足够多的停电数据。所提规划方法采用重要性采样技术和双层优化策略从不同层次减少规划流程的计算量。Garver 6节点系统的测试结果验证了所提规划方法的有效性。
A method of multi-stage TEP(Transmission Expansion Planning) considering large-area outage risk is proposed and an index of PTR(Power-law Tail Risk) is defined. The large-area outage risk is evaluated by the variation trend of outage area tail distribution. An OPA model is developed based on the SOC(SelfOrganized Criticality) theory to obtain the statistic outage data corresponding to multi-stage TEP,which considers the coupling relation between adjacent stages in the slow dynamics and the hidden failures in the fast dynamics,respectively reflecting the impact of the TEP behaviors in the long time scale and the cascading failure behaviors in the short time scale on the global dynamic characteristics of power system. The long-term evolutionary behaviors based on the average effect are cancelled in the slow dynamics and the Monte Carlo simulation is used in the fast dynamics to obtain sufficient statistic outage data. The importance sampling technique and bi-level optimization strategy are applied in the proposed method to lower the computational load of each level. Case study for Garver 6-bus system confirms its effectiveness.