Research On Risk Assessment And Weak Link Identification Method Of Distribution Network Under Typhoon Meteorological Conditions

Typhoon is a common extreme weather that poses a great threat to the distribution network in some coastal areas and brings huge losses to the power grid.In order to improve the power supply reliability of the distribution network under typhoon conditions,it is necessary to establish a risk assessment method for the distribution network and analyze the characteristics of risk changes.Therefore,based on the establishment of a method for calculating the failure probability of overhead lines in the distribution network under the influence of multiple factors,the Monte Carlo simulation method is used to realize the dynamic risk assessment of the distribution network under typhoon weather conditions,and proposes a weak distribution network The main work of the link identification method is as follows:(1)Study the calculation method of the failure probability of overhead lines under typhoon weather conditions.Firstly,calculate the typhoon wind speed value at each point in the typhoon wind field based on the Batts model,and use the micro-topography to make corrections.Secondly,by studying the principle of overhead line failure caused by typhoon,a calculation method for the failure probability of overhead line with wind speed under typhoon weather conditions is constructed,and the failure probability of overhead line is corrected based on the service time.Finally,through case analysis,the influence of multiple influencing factors on the failure probability of overhead lines is studied.(2)A method for dynamic risk assessment of distribution network under typhoon weather conditions based on Monte Carlo simulation is proposed.Firstly,the product of the failure probability and the load capacity of each load point is selected as the risk index of the distribution network under typhoon weather conditions,and seven variables such as typhoon wind speed are selected as the risk factor of the distribution network.Secondly,based on the failure probability of the overhead line,Monte Carlo simulation method is used to calculate the failure probability of the overhead line at different times during the entire typhoon process,and on this basis,the dynamic risk assessment of the distribution network during the typhoon process is realized.Finally,analyze the influence of the changes of different risk factors on the risk value of the distribution network.(3)A method for identifying weak links in the distribution network under typhoon weather conditions is proposed.Firstly,select the line failure probability,line load importance and line failure development situation as the evaluation indicators of weak links,and build the weak link evaluation system of the distribution network under typhoon weather conditions.Secondly,according to the definition,each evaluation index of the weak link is quantified in turn,and the analytic hierarchy process is used to calculate the weight of each evaluation index.Finally,Monte Carlo simulation is used to identify the weak links of the distribution network under typhoon weather conditions,and analyze the characteristics of the weak links of the distribution network under typhoon weather conditions.