Research On Toughness Evaluation And Defense Measures Of Urban Distribution Network Under Typhoon Disaster

In recent years,under the joint action of global warming and other reasons,the probability and intensity of extreme natural disasters such as typhoons are increasing,resulting in large-scale power outages from time to time,posing an increasing threat to the safe and stable operation of urban distribution networks.In order to improve the ability of urban power grid to resist typhoon disasters,it is necessary to improve the toughness of urban distribution network under typhoon disasters.This paper focuses on the modeling of the impact of typhoon disasters on distribution networks,the toughness evaluation of distribution networks,the establishment of evaluation index system and typhoon prevention measures,so as to provide theoretical and technical support for improving the ability of urban distribution networks to resist typhoons.Firstly,the impact of Typhoon on urban distribution network is analyzed,and a model describing the disaster causing factors and a duration model are established from the two dimensions of time and space to quantify the intensity of typhoon disasters.Based on the Monte Carlo simulation method,the component failure probability model of urban distribution network is established,and the mapping relationship between the typhoon disaster intensity and the component failure probability of urban distribution network is obtained.The Monte Carlo simulation method is used to simulate the urban distribution network failure scenario.The effectiveness of the proposed method is verified by the analysis of typhoon examples,which lays a foundation for the subsequent study of the toughness evaluation index system and evaluation method of urban distribution network under typhoon disasters.Then,the research on the evaluation index system of urban distribution network toughness is carried out,and the evaluation index system of distribution network toughness is established,which includes three criteria layers: the expected strength of distribution network,the resistance ability of distribution network,and the efficiency of power recovery and repair.The research on the resilience evaluation method of distribution network is carried out,taking into account the space and time scales of the occurrence and development of typhoon disasters,the random fault outage of distribution lines depending on the intensity of typhoon disasters,the load transfer in disasters and the power supply recovery process after disasters.A quantitative evaluation framework of resilience of distribution network covering multiple stages and levels is proposed to better evaluate the resistance and response ability of distribution network to disasters under extreme typhoon weather,It has good engineering practicability.Finally,based on the improvement of the resilience level of the distribution network,the typhoon prevention measures of the urban distribution network in both pre disaster and post disaster dimensions are studied,and a vulnerability index based identification method and defense measures for the weak links of the distribution network are proposed.The weak links of the urban distribution network are sampled by Monte Carlo simulation method,and measures such as strengthening or allocating emergency power generation vehicles for power supply by key components are taken;An optimal dispatching model for distribution network reconfiguration and rush repair is proposed,which optimizes the path of maintenance personnel and the repair order of fault components after disasters,so as to improve the efficiency of rush repair and load recovery.The effectiveness of the proposed typhoon prevention measures before and after disasters on the resilience of urban distribution networks is verified by numerical examples,which has important guiding significance for guiding the development of disaster prevention,resistance and mitigation of urban distribution networks.