Research On Condition-based Maintenance Strategy Of Relay Protection Device In Smart Substation

The development of relay protection technology in smart substation starts relatively late and many indefinite factors still exists.Compared with conventional protection equipment,the protection device of smart substation has changed greatlly,which makes the operating and maintenance methods changed a lot as well.In view of the great progress of condition-based maintenance in primary equipment application,the condition-based maintenance stategy of relay protection equipment for smart substation is analyzed in this paper,a condition-based maintenance strategy is proposed based on Weibull proportional hazards model.Taking the smart station of Cangzhou power supply company as an example,the model strategy is discussed.Firstly,the condition-based indicator set of relay protection equipment in smart substation is established in this paper after studying the aspects of selection basis,content,sources etc.The Weibull proportional failure model strategy is determined to be applied to research the condition-based maintenance of relay protection equipment through comparative analysis.Sencondly,a condition-based maintenance stategy is proposed based on the Weibull proportional failure model.In the strategy,at a certain time t,it shows that the operation state of the equipment is deteriorating if the devices satisfy the condition-based maintenance mode;otherwise,the equipment is in nomal operation.Thirdly,the parameters' estimation algorithm of Weibull proportional failure model is improved,and a separate estimation algorithm is proposed,then the maximum availability method is studied.Then,the scoring rules of the historical operation condition-based indicators and the real-time operation condition-based indicators of the smart station protection device are analyzed to get the scoring methods of each condition-based indicator.After that,the condition-based maintenance stategy on account of proportional failure model is introduced and the implementation steps and process are analyzed.Finally,a statistic analysis is carried out to study the historical operation condition-based indicators and the real-time operation condition-based indicators of PCS-931 protection device.The parameters of Weibull proportional failure model are estimated by using the separation estimation algorithm,and the maintenance threshold function is solved by applying the maximum availability method.The case studiies validate the effectiveness of the proposed strategy.