TRANSFORMER OIL PERFORMANCE TESTING USING CORRELATION COEFFICIENT METHOD

The performance of transformer oil as a cooling insulator determines the electric power distribution system. Transformer oil should be tested regularly. The main parameters are Total Dissolved Combustible Gas (TDCG) by using Dissolved Gas Analysis (DGA) to measure the quantity of dissolved gas, Breakdown Voltage to measure the ability of oil insulate the electric voltage, and Water Content to measure the water content in the oil. This research examines the relationship between the main parameters. Four samples of transformer oil for 150 KV power indicated that initial failure occurs due to corona, arcing, and overheating of cellulose at low energy levels. The TDCG has a weak correlation to Breakdown Voltage and Water Content. The Breakdown Voltage and Water Content have a strong correlation with each other. Transformer oil testing is recommended to be conducted regularly every 3-6 months, while the replacement depends on the condition and age of the transformer oil.