Power transformer is a key link in power distribution system without which electricity supply cannot reach the consumer safely. Their unexpected failure can cause, inconvenience, outage to high number of consumers and loss of capital to the utility. Correct application of diagnostic technologies and acceptance test is important in preventing any unwanted failure.
This project aims to discuss about role of medium to low voltage power transformers in the distribution network and with an experimental application of the diagnostic methods, 3-phase transformers were tested using the insulation resistance measurement technique and the winding resistance measurement that were performed in the High Voltage Laboratory.
In our world today, bringing energy safely to consumer is applicable with the use of power transformers, which is a key in power networks, by stepping voltages up for transmission and down for distribution. Research is been carried out on power transformers with an increasing demand for stable, high quality power supply. Application of diagnostic technology plays a very important role in evaluating conditions, performance and preventing catastrophic failures as such copper windings must be rated to handle the full load current, short time over currents, the magnetic circuit and insulation must be able to cope with the rated system voltage, allowing for over voltages in which it must be adequately insulated to prevent insulation failure to the earthed iron core, between windings and inter-turn. Insulation is one of the most important constituents of a transformer; any weakness in the insulation may cause failure of transformer. To ensure effectiveness of the insulation system of a transformer must confirms the dielectric test.