What causes bad D1816 dielectric breakdown voltage values? The first article in this series will discuss the three standard methods that SDMyers is equipped to perform, and why we perform them for our customers. There are two standard methods from ASTM International: D877, Standard Test Method for Dielectric Breakdown Voltage of Insulating Liquids Using Disk Electrodes, and D1816, Standard Test Method for Dielectric Breakdown Voltage of Insulating Oils of Petroleum Origin Using VDE Electrodes.
There are very few organizations that are not concerned with following reliability best practices. It is more efficient and less expensive to prevent a breakdown than it is to fix something that breaks. Monitoring and data management are becoming ubiquitous in the industrial world, the utility world, and across most industries and sectors as we work towards a more reliable and interconnected future. Electric power systems have not been included in this shift away from break/fix and towards data-centric reliability, and what the future holds for organizations seeking best practices.
One of the most important functions of oil in a transformer is to protect the paper (solid insulation). As oil ages, it loses its ability to protect the paper from degradation. Aging also weakens the oil’s ability to act as a cooling medium and provide dielectric strength – ultimately protecting the transformer from failure. Through the aging process, chemical by-products build up in the oil and the paper, creating acid by-products and sludge. These decay products begin to affect the oil’s protective qualities almost immediately after they form, they begin to break down the molecular structure of the solid insulation.
Michel Duval developed the Duval Triangle, based on the use of three hydrocarbon gases, in the 1960s as a more accurate method of interpreting transformer oil testing results.