Assessing And Boosting Resilience Of Distribution System Under Extreme Weather

As the global climate change in recent years,Distribution system blackouts with serious economic losses and social impact may occur under frequent extreme weather disaster.As the terminal of power grid,the key link in the process of direct power supply to the user,the normal operation of distribution network in the extreme weather conditions is especially significant to maintain the stability of the social and economic development.So the resilience is introduced to reflect the ability of distribution network to withstand extreme weather hazards,to reduce the loss of failure,and to run back to the original state as soon as possible at the end of the disturbance.Distribution network resilience analysis is an important theoretical basis for the research of improving power grid resilience.Distribution network element is numerous and the analysis of fault scale,response and failure repair process is more complex,so it is very necessary to establish a relatively perfect resilience analysis method,which is more suitable for distribution network.In order to reduce the power losses during extreme weather,it is necessary to research mearures to improve the distribution network resilience.At present,the research is focused on the traditional methods,such as cable and replacement of high intensity line,but the high cost investment limits the application value of such measures.The access to distribution network of distributed generation supplies a major breakthrough to improve the resilience study.After components damaged by extreme weather,distributed generation can provide power to critical load in the system,but the access of DG increases stochastic volatility of power grid,so it is necessary to accurately quantify the corresponding distribution network resilience.For this purpose,assessing and boosting resilience of distribution system under extreme weather are studied.Firstly,this paper distinguished the different between distribution network resilience and reliability and put forward the distribution network resilience analysis method.The influence mechanism of extreme weather on distribution network element failure rate is introduced;failure scenarios are selected based on Shannon entropy and the possible blackout level is confirmed.Resilience evaluation method was proposed considering load loss in different scenarios.Secondly,the probability distribution of resilience was obtained by non-parametric kernel density estimation,which can fully reflect the contribution of stochastic fluctuation distributed generation to distribution network resilience.Finally,the principle of distribution network boosting resilience measure analyzed.Traditional hardening method optimizing the components repaired sequence is proposed.The effect of resilience boosting measures is compared by analyzing the results of the case study,which veriies effectiveness of the proposed approach in this article and the practical value of resilience boosting measures.