Maintenance schedule of transmission system based on equal risk

With the rapid development of the power grid, the importance of transmission system maintenance is receiving ever-increasing attention. This paper investigates the transmission system short-term maintenance strategies from the angle of the whole transmission system. Firstly, the components to be maintained are selected by equipment monitoring technology. As it is difficult to acquire component's sensitivity to system reliability by disconnection analysis, this paper proposes the affected electrical quantity to evaluate the equipment importance level, which can improve computational efficiency. The optimal maintenance sequence is formed accordingly. Then the transmission system optimized maintenance model based on the equal-risk theory is given by referring to generator maintenance strategies. The model has taken the maximum reduction of load shedding risk as the objective function. Reliability index variation during the maintenance period has been taken as the key parameter, while dynamic variation of equipment failure rate after maintenance, labor resource and budget constraints are also taken into consideration. Finally, the heuristic algorithm is employed to solve the proposed model. Case studies testify the feasibility and validity of this model. © 2012 State Grid Electric Power Research Institute Press.