Enhancing reliability and life span of transforMer through innovative condition monitoring techniques Shrivastava Jyoti1, Shrivastava C.M.2 1Allahabad Agriculture University, Allahabad, India. 2Bharat Heavy Electrical Ltd., Bhopal, India. synopsis In today's competitive environment, it is imperative to capitalize on advances in technology that allow new technique for maintenance of the electrical equipments. As the entire energy has to pass through the transformer, it becomes necessary that transformer must give long and trouble free service. It is very important that transformer must receive a reasonable degree of attention regarding its health. During recent years policy of utilities is changing under the pressure of economical consideration. There is common tendency of moving the time based to the condition based maintenance. It reduces cost and prevents sudden failure particularly catastrophic, ones that follow main insulation faults, arcing & heating. Sometimes under compulsion it is necessary to keep transformer in operation when indications of arcing, heating, partial discharge are prevailing. Condition monitoring is the only tool to handle such situation. Paper presents some newer on line diagnostics methods.It describes the various on line condition monitoring technique such as Dissolved Gas Analysis, Moisture monitoring, Thermal scanning, Partial Discharge measurement, Bushing monitoring. Case studies are given for DGA, Thermal scanning. Sum of current parameter is a very reliable indicator of dangerous trends in bushing insulation system. In addition modern microprocessor based instrumentation allows for additional diagnostics performed on line. Online diagnostics provides valuable information, which helps in maintenance strategy as a result save time and money. Different techniques such as Estimation of Furfural content, Degree of Polymerization and methodology adopted for life estimation of transformer winding insulation are also covered. Continuous efforts and developments are in progress in this area to facilitate preventive action on the transformer to avert catastrophic failure. Top Key words On line monitoring, Dissolved gas Analysis, Partial discharge, Transformer, Bushing monitoring, Fiber optical sensors, Degree of polymerization. Top |