Abstract: In order to improve the efficiency of power grid equipment maintenance，an evaluation index of

equipment maintenance value based on Markov model was proposed，and an optimization decision method of power grid maintenance based on maintenance value evaluation was constructed. The value evaluation index of power grid equipment maintenance based on four-state Markov model was put forward by considering the increase of its own value and maintenance input cost before and after equipment maintenance. According to the order of maintenance value，a sequential forward search algorithm was used to optimize the maintenance of power grid equipment. By counting the change process of key indicators such as power grid operation risk and power generation capacity under different equipment maintenance scope，the scope of maintenance equipment and its maintenance plan were determined. The example shows that when the decision index obtained from the tentative optimization exceeds the decision threshold，the optimization decision method will output the maintenance range and maintenance plan of the equipment at the same time. Compared with the traditional method，the results show that the proposed maintenance value evaluation index can fully consider the equipment failure rate and its own value，which is helpful to improve the comprehensive benefits of the power grid.

      Key words: power grid maintenance；equipment maintenance value；Markov model；sequence forward

search algorithm