Desgin of On-line Monitoring Device for MOA (Metal Oxide Arrestor) Based on FPGA and C8051F

Abstract

Monitoring of metal oxide surge arresters (MOA) due to aging, moisture and other components cause increased resistive current. Through a lot of practices, it has been proved that in the early days, MOA insulation damage and current increase is not obvious. The accurate working conditions of the MOA are also not obvious but it can reflect the aging or moisture of MOA. When the resistive current of the fundamental component increases, there is no increment in the harmonic components that is the general performance of a serious or moisture contamination. In the same way when the resistive current of harmonic components increases, the fundamental component is not increased and it is the general performance of aging. Therefore, this paper designed an experiment-based FPGA and C8051F-line monitoring device. This device uses resistive current as a detection target. The main monitoring parameters are the fundamental and peak value of resistive current, third harmonic content of the leakage current, phase angle difference and power consumption. Through laboratory tests, the device can be used with a network arrester line monitoring, maintenance, reduce the economic losses caused by power outages and improve the distribution network reliability