EXPERIENCE AND STRATEGIES FOR REFURBISHMENT OF PROTECTION AND CONTROL SYSTEMS IN JAPAN

摘要

This paper reports experience and strategies forrnrefurbishment of protection and control systems inrnJapan's electric power companies. Additionally, itrnreviews the technology involved in such systems basedrnon the survey and research conducted jointly by thernelectric power companies in Japan.rnAs an indicator for use in judgment to refurbish thernanalog-type protection equipment, they studied thernrequirement by the power system changing, the failurernstatistic and the component remodeling/discontinuationrnbased on from 20 to 25 years. A proposal was presentedrnfor methods of rationally making decisions onrnrefurbishing analog-type protective equipment by scoresrnbased on these assessment indicators.rnRegarding control systems, electric power companiesrntend to place priority on such reasons for replacementrnas increased functionality based on latestrncommunication technology and numerical technologyrnand general cost cutting through system integrating andrnreplacement, rather than the concepts of replacementrnbased on assessment indicators for protective equipmentrnfrom the trends and the surveys. As a result, the averagernsystem usage is almost20 years.rnFinally, we describe the prospect of these equipmentrnand systems. The cost reduction is progressed byrnselecting a suitable refurbishment time for thernprotection and control system and by integrating therncontrol system.