Investigation and comparison of insulating oil properties using various analytical methods

In the current scenario, rising energy consumption has put a significant burden on transformers. Simultaneously, power utility companies are reducing their capital investments. As a result, industrial consumers are increasingly focused on maintaining the trouble-free operation of their existing transformers to ensure their reliability remains intact. The reliability of the transformer heavily counts on the health and condition of its insulating oil and the various physicochemical and dielectric properties associated with it. Various national and international organisations, such as ASTM, IEC, and IS (Indian Standard), have established standardised test methods to evaluate the insulating oil properties. These tests help in assessing the oil’s quality and the transformer’s condition. Monitoring the properties of insulating oil using established test methods is vital for assuring transformer reliability. It allows for early detection of potential issues and enables timely maintenance or replacement actions to prevent costly failures. This paper aims to analyse and compare the key properties of mineral insulating oil including breakdown voltage (BDV), water content, IFT, and acidity, utilising ASTM, IEC, and IS standard test methods to assess the accuracy and uniformity of the test method. The results serve as a valuable resource for analysts and professionals.