Research On Condition Maintenance Decision Of Distribution Network

As an important part of power system management, reasonable maintenance willimprove equipment utilization, reduce the failure probability of the grid, and ensure asafe and reliable operation of power system. As a preventative maintenance,condition-based maintenance according to deterioration degree of device dynamicallyadjusts the equipment maintenance time, which makes the maintenance more targeted.With the deepening of condition-based maintenance system, it puts higher requirementsfor power grid maintenance work.In this paper, it summarized the research results including three aspects ofcondition-based maintenance: condition monitoring, condition evaluation andmaintenance decision. The main work is as follows:1) Introduce the condition evaluation methods of the distribution networkequipment of State Grid Corporation of China, which includes: equipment informationacquisition, principles and methods of condition evaluation. The equipment is dividedinto different units, and obtains state quantities of each unit of the equipment. Introducethe score deduction system from two aspects like component evaluation and overallevaluation.2) It set up the relation between the equipment health index and the failure ratebased on the results of condition evaluation. This paper brings in aging coefficient andhealth repair factor to predict equipment health status at a certain moment in the futureand the improvement of equipment health status after maintenance. Finally, it solved thefault probability of equipment according to the relationship between the equipmentfailure rate and reliability.3) Since the equipment in a certain state could choose different maintenance levels,which have different impacts on maintenance time、 maintenance costs and theimprovement of equipment state, which will in turn affect the time schedule ofequipment maintenance. Therefore, both the maintenance mode and the maintenancetime are viewed as decision variables of making maintenance schedules. Based on themethod of risk assessment, the overall risk of grid operation and the revenue ofequipment maintenance are defined in this paper. Furthermore，since the single riskindicator for the final decision is not comprehensive. And the maintenance results ofsingle optimization model have different impacts on the economy of equipmentmaintenance and the reliability of equipment after maintenance. Therefore a jointoptimization model integrating the overall risk of grid operation and the revenue ofequipment maintenance is established. Then compared with the three maintenance schedules to analyze the maintenance effects on equipment reliability and economy. Theresult of application verifies the validity of the method.