Testing and Planning of Load of Oil-Immersed Transformer when Non-linear Load Condition in Bangkok and Surrounding Area

Abstract

This paper presents the testing and planning of using oil-Immersed transformer under non-linearload and over load condition in Bangkok and surrounding area. The purpose of this research is to extendthe lifetime of oil-Immersed transformer. The simulation of load cycles and calculation of top oiltemperature, hot-spot temperature, top oil temperature rise, hot-spot rise temperature, loss of life andlifetime of transformer were presented. There were 4 conditions of temperature of the transformer fromsimulations : 1) yearly average constant ambient temperature ; 2) yearly varying ambient temperatures ; 3)control of ambient temperature at 25 ^oC and 4) varying ambient temperatures in a year and load cycleadjustment. The result showed the damage protection of a transformer due to overrated heat andapplication to transformer's other areas at different ambient temperatures or with large (kVA) transformers.