Research on the electrical performance variation characteristics of internal damp roof arrester of EMU

Abstract

In order to study the reason of performance deterioration of roof arrester, this paper conduct the disassembly inspection of the burst arrester, and conducts the SEM test and EDS test to the valve plates, and the microscopic variation characteristics of the valve plates were analyzed and the electrical parameters variation characteristic under different internal damp was studied. Microscopic test results show that the white matter on the valve plate surface is caused by moisture oxidation of the aluminum spray layer. The results of simulation damp test show that the DC reference voltage decreased obviously, it is only 55.2 kV even under mild damp, which is lower than the standard value of 58.0 kV. At the same time, the leakage current rises to 46 μA under 0.75 times of DC reference voltage, and the full current reaches 1.21 mA under 42 kV with AC voltage. The peak value of the fundamental wave of the resistive current reached 1.35 mA.

Keywords

• Arrester
• Disassembly
• Microscopic testing
• Moisture