MODULE: Operation And Maintenance Of Transformer ( O&M 1 )


Introduction: Principle of operation; Vector Group; Two winding and Three winding Transformer; Rectifier Transformer; Parallel operation and Load Sharing.

Protection: Over load, Over current; Differential; Restricted Earth fault; Buchholz.

Maintenance Test: Routine maintenance testing; IR, PI, Dielectric absorption, High- Pot; tan d, DC winding resistance, TTR (Transformer turns ratio), Magnetic Balance; Acceptable Values.

Drying of Transformer: Short circuit heating and hot air circulation.

Oil: Definition of terms used in oil characteristic; acceptable values for BDV, tan d, specific resistance, neutralization value, interfacial tension, gas content, oil filtration techniques – Fuller’s earth, Enervac, and Velcon system; DGA (Dissolved Gas Analysis), Principle, Roger’s method, Limiting value of Hydrocarbon concentrations, Case studies, Condition monitoring, recommended test, and periodicity.