Research On The State Evaluation Method And System Of Secondary Equipment In Smart Substation

With the popularity of smart substation,the connection points of the power grid have been gradually intelligentized,which supports the development strategy of the national smart grid.However,the backward substation equipment maintenance mode has become an obstacle for the safe and stable operation of smart substations.The traditional periodic maintenance can not avoid equipment accidents and even bring additional damage to equipment in terms of excessive maintenance,so condition based maintenance is imperative.In terms of the limited technology,it is difficult to realize condition based maintenance of primary equipment in a short time,but the high-speed development of network communication technology may realize conduction based maintenance of secondary equipment.Therefore,how to operate condition based maintenance of secondary equipment in smart substations has become an significant research topic.Aimed at the existing problems in condition based maintenance,this paper studies the basic condition evaluation of condition based maintenance,and designs a set of smart substation secondary equipment condition evaluation system with the main functions of online monitoring and condition evaluation.The system can complete on-line monitoring of secondary equipment in the station,monitoring of network topology diagram,control of SCD files,and status evaluation.Firstly,by analysis of the available state parameters inside the secondary equipment of the smart substation,we can extract the key information representing the operation state of the secondary equipment,and establish a state evaluation index system including the merging unit,the intelligent terminal and the protection and monitoring device pursuant to the characteristics of different types of equipment.Secondly,through analysis and comparison,the initial weight of each evaluation index is determined by Analytic Hierarchy Process and the variable weight theory is introduced to deal with the weight,so as to establish the weight calculation model based on the variable weight theory.Thirdly,the evaluation indexes are classified into forward direction,reverse and interval to establish the evaluation index scoring model.Then the weight model and the scoring model are combined to establish a secondary equipment state evaluation model.Finally,pursuant to the secondary equipment state evaluation model,a secondary equipment state evaluation system is designed by computer information technology.The three-level system structure including data acquisition unit,data processing and calculation unit and application unit can complete the functions of on-line monitoring of secondary equipment in the station,monitoring of network topology diagram,control of SCD files,and state evaluation.The test results show that the system can effectively solve the problem of condition based maintenance of secondary equipment in 110 kV smart substation,reduce the times and time of secondary equipment maintenance,improve the safe and stable operation level of 110 kV power grid with high practical and promotional value.