Laser Raman spectroscopy applied in detecting dibenzyl disulfide(DBDS) in transformer oil

Recently, copper sulfide which was formed by corrosive sulfur in transformer oil reacting with copper windings caused many faults of high voltage electric equipments. Online detection of dibenzyl disulfide (DBDS) has become a new way of avoiding happening major accident. Comparing with the traditional monitoring technologies, Laser Raman spectroscopy (LRS) has incomparable advantages, such as non-contact detection, quickly integrated detection of multiple characteristic substances, using single-frequency laser, which are necessary to achieve online monitoring. Based on the basic principle of LRS, we build up a platform using LRS for quantitative and qualitative analysis and develop the relevant experimental methods. Thermal aging tests are done at 140 °C with an air atmosphere up to 48h with copper strip. The test results indicate that Laser Raman spectroscopy can be applied to identify corrosivity of mineral oil for a running power transformer.