基于网络结构重要度和安全隐患脆弱度的配电网脆弱线路辨识

为了辨识配电网中的脆弱线路,提出一种基于网络结构重要度和安全隐患脆弱度的线路综合脆弱性评估模型。该模型一方面以复杂网络理论基本参数结合配电网的特点定义了线路的网络结构重要度指标,另一方面以负荷冲击和故障断线两种情况对系统安全运行造成的影响定义了线路的安全隐患脆弱度指标。通过层次分析法(Analytic Hierarchy Process,AHP)计算各指标的权重系数,从而综合反映线路的脆弱性。以IEEE33节点配电系统进行计算分析,验证了该线路综合脆弱度评估模型具有合理性和有效性。

Research on large-scale cascading failure of power systems using synergistic effect

This paper discusses the primary causes from the point of synergistic effects to improve power system vulnerability in the power system planning and safety operation. Based on the vulnerability conception in the complex network theory the vulnerability of the power system can be evaluated by the minimum load loss rate when considering power supply ability.Consequently according to the synergistic effect theory the critical line of the power system is defined by its influence on failure set vulnerability in N-k contingencies.The cascading failure modes are proposed based on the criterion whether the acceptable load curtailment level is below a preset value.Significant conclusions are revealed by results of IEEE 39 case analysis weak points of power networks and heavy load condition are the main causes of large-scale cascading failures damaging synergistic effects can result in partial failure developed into large-scale cascading failures vulnerable lines of power systems can directly lead the partial failure to deteriorate into a large blackout while less vulnerable lines can cause a large-scale cascading failure.

防止返贫动态监测和精准帮扶的着力点——基于CFPS数据的实证分析

脱贫摘帽不是终点,而是新生活、新奋斗的起点,巩固拓展脱贫攻坚成果必须要重视摆脱绝对贫困后可能的返贫问题。本文立足于2020年后中国防止返贫动态监测和精准帮扶的现实需要,采集2010-2018年CFPS的五轮调查数据,通过反推VEP法测算脆弱线来甄别确定中国农村返贫治理的瞄准对象,然后依托有序Logit模型揭示瞄准状态动态变换的根本诱因。结果发现:(1)经过不同临界值比较并参照已有的返贫监测标准发现,2018年33%贫困脆弱性水平对应的5151元脆弱线是甄别瞄准对象和非瞄准对象的合适标准。在这一标准下,瞄准对象占比在分析区间内有所下降,且瞄准对象和非瞄准对象的动态变换较快,摆脱返贫风险和陷入返贫风险同时存在。(2)人力资本和物质资本因素有利于家庭摆脱瞄准状态,依赖于政府补助和省级财政转移支付的家庭容易持续处于瞄准状态,不同规模和年龄的家庭具有明显的异质性。上述结论对"十四五"期间健全防止返贫动态监测机制和找准精准帮扶的着力点具有重要的指导意义。