基于改进功率介数的电网风险评估

针对国务院599号令《电力安全事故应急处置和调查处理条例》以及《中国南方电网有限责任公司电力事故(事件)调查规程》中强调电网发生事故后对用户侧产生的影响,提出考虑发电机和负荷的社会属性的改进功率介数。利用改进功率介数衡量线路和节点的重要度,并将改进功率介数引入到电网故障后果指标,克服传统风险评估方法对发电机和负荷社会属性及潮流流动影响考虑不足的缺陷。故障后果指标选取了考虑电网一次系统权重和二次系统权重的网络效率、电网的加权潮流熵、电压偏移严重程度以及负荷损失严重程度。针对上述故障后果指标,提出采用直觉模糊层次分析法,同时考虑决策过程中隶属度、非隶属度、犹豫度三方面信息,更为客观地评价电网故障后果的严重度。采用非序贯蒙特卡洛法计算故障概率,最终得到电网故障风险。算例结果表明,所提出的基于改进功率介数的电网风险评估方法可以在强调负荷社会属性的情况下更好评价电网风险。

Power grid risk assessment based on improved power betweenness

For the State Council Decree No.599 "Electrical Safety and Accident Investigation and Handling Emergency Regulations", and "China Southern Power Grid Co., Ltd.,Electrical Accidents (Incidents) Investigation Procedure (Trial)" stressing on the user side of the grid after an accident, the improved power betweenness is put forward which considers the social property of generator and the load. The improved power betweenness is used to measure the degree of importance of lines and nodes, and the improved power betweenness is brought into grid failure consequences index to overcome the traditional risk assessment methods which have deficiencies in short of considering social property of the generator and the load and current flow influences. Indicators of failure which include network efficiency considering the primary system and the secondary system weights, the weighting entropy of grid flow, the severity of the voltage offset and severity of load loss. For the consequences of the failure indicators, intuition fuzzy analytic hierarchy process, taking into account the decision-making process membership, non-membership, hesitation of information in three areas which gives a comprehensive assessment of grid failure consequences. The non-sequential Monte Carlo method is used to calculate the probability of failure, to obtain the final grid failure risk. The example shows that the proposed method which is power grid risk assessment based on improved power betweenness can effectively measure the power grid risks in the case of emphasizing the importance of load.