Experimental Study on Fault Process of High Energy Arch Discharge in the Oil Chamber of OLTC

The fault of high energy arch discharge in the oil chamber of OLTC can vaporize transformer oil instantly to produce high pressure bubbles, and to increase the pressure in the oil chamber quickly. When the relief valve cannot release the pressure effectively, the high pressure from the arch fault will destruct the oil chamber structure or even cause a fire or explosion. To study the pressure distribution and evolution characteristics during arc fault in the oil chamber of OLTC., high-precision pressure sensors were used to capture the pressure changes at different positions in the oil chamber during high energy arch discharge. The result shows that when a fault of high energy arch discharge occurred., the pressure peak captured on the side wall of the oil chamber was 4.2Mpa; the pressure peak at the bottom of oil chamber was 4.9Mpa; the pressure relief valve on the top of the oil chamber opened 7.4ms after the arch fault occurred, and the pressure peak on the top of the oil chamber was 5.3MPa. The test result of this study can provide effective references for the safety protection design of OLTC oil chamber arc fault.