Traditional maintenance plans of distribution network focus on grid structure and load while ignoring equipment difference and real-time equipment status. In order to solve the problems

we established an optimization model of distribution network maintenance plan based on equipment condition evaluation and grid loss risk calculation

put forward a calculation method of the matrix between an equipment health index and a failure rate in the future analysis time

and presented the key parameters. Based on the dynamic failure rate and the distribution network topology

the minimum road method was adopted to obtain the failure rate and the load point failure time of the whole distribution network under normal conditions and maintenance conditions. Then

the risk model of the loss of a power grid caused by failure

the loss of equipment failure

the loss of the power grid caused by maintenance

and the loss of the equipment caused by maintenance were established based on the risk of the loss of the power supply

the importance of the load point

the equipment value

and the maintenance cost. The results show that the optimization model proposed in the paper comprehensively considers the risk decision value calculated by the above risk model

realizing the optimization of the maintenance plan. Meanwhile

the historical average failure rate in the process of the traditional maintenance plan was replaced by the dynamic change failure rate

overcoming the traditional condition evaluation disadvantages caused by the maintenance without taking the weak power distribution network into account. Finally

the model was used to calculate an actual case of a distribution network in Nanjing

and the decision values of distribution network risk were obtained.The calculation results show that the risk value of the distribution network is not necessarily determined by single risk factor such as multiple equipment

heavy load

and late maintenance time

the overall cost of the maintenance plan determined by the model is lower than other schemes and it meet the needs of actual projects. The research results validate the feasibility of the optimization of the distribution network maintenance plan based on the equipment status evaluation

and the proposed method is also applicable to the maintenance plan optimization of the higher voltage level network.