Maintenance Schedule Optimization For Distribution Network Considering Life Cycle Cost

Distribution equipment maintenance is an important content of distribution network operation. The rationality of maintenance schedule not only affects both power enterprises and users, but also has a far-reaching influence on the safety and economic benefit of the whole society. With the development of distribution network and the improvement of power equipment quality, the transition from the traditional planned maintenance to condition-based maintenance is the trend of the distribution network development. The implementation of condition-based maintenance is the requirement of the times.After summarizing the existing achievements of distribution network condition-based maintenance, the study of how to make distribution network condition-based maintenance schedule has been conducted in this paper. The issues involved in condition-based maintenance such as the process of equipment status evaluation, the concept of risk assessment and maintenance schedule optimization have been made a deep analysis.The main contents are as follows:(1) Thr related content of equipment condition-based maintenance is introduced, which mainly includes the information collection, the status evaluation and the failure rate calculation of equipment. In addition, the concept of risk assessment is introduced, and the principle of the risk assessment based distribution equipment condition-based maintenance is explicated in detail. Condition-based maintenance based on quipment life cycle cost is introduced briefly, which lays a foundation for establishing the maintenance decision optimization model later.(2) Aiming at the distribution network maintenance decision optimization problem, taking maintenance time and maintenance mode as optimization variables, the multi-objective optimization model of distribution network maintenance is established aiming at minimizing the distribution network maintenance risk and fault risk. Then the Pareto optimal solution set of the model is obtained by the distance sorting multi-objective particle swarm optimization algorithm. Considering both subjective preference factor of decision makers and objective information of the actual system, the multi-attribute decision-making method based on the fuzzy entropy weight of Vague set is adopted to make decision. Then the most satisfactory maintenance schedule will be selected. Finally, the effectiveness of the proposed method is validated by optimization results for RBTS Bus2 and RBTS Bus6 distribution system respectively.(3) In order to extend the maintenance schedule optimization to equipment lifespan, from the perspective of the optimal life cycle cost, the specific equipment maintenance strategy is formulated in this paper. The maintenance time and the maintenance mode are taken as the optimization variables; maintenance capacity constraints, grid security constraints and other constraints are considered; the distribution network maintenance schedule optimization model based on equipment LCC is established aiming at minimizing the distribution equipment life cycle cost. According to the feature of the model, the most satisfactory maintenance schedule will be selected by adopting the multi-objective optimization algorithm and the multi-attribute decision-making method. RBTS Bus6 distribution system is given to demonstrate that the maintenance strategy based on LCC considers both subjective preference of decision-makers and objective information entropy of the actual system, improving the maintenance efficiency based on the power supply reliability guaranteed. Consequently, the rationality of the model discussed is validated.