Development Of Substation Metal Oxide Arrester State Detection Device

Safety of substation high - voltage equipment concerns the entire power grid safety, due to the widespread use of Metal Oxide Arrester(MOA), MOA State Detection is both necessary and is the development trends.MOA State detection device designed in this article include two main parts, MOA resistive current measuring devices and the PC monitoring software. Experimental demonstration shows that resistive current of MOA is a key characteristic parameter of the MOA state change. As the existed MOA resistive current measurement methods have many defects and problems, a new MOA resistive current measurement method is presented based on IEEE1588 and wireless data transfer. This measurement method uses time synchronization module that supports IEEE1588 protocols and wireless communications to accomplish synchronised measurement of MOAs'voltage and current. Its advantages are simple field wiring and not limited by space location of substation. In addition, for traditional harmonic analysis algorithms based on Fourier series have disadvantages of spectrum leakage and hurdle effect in calculating phase difference between voltage and leakage current, a fundamental harmonic phase separation algorithm based on digital filtering is proposed. Simulation shows that in the frequency fluctuations the new algorithm performance significantly better than traditional algorithms. This article also designed the USB2.0 interface - based data transfer modules and PC monitoring software based on Visual Basic. The measured data can be transferred to the host computer through the USB interface and PC monitoring software has functions of data queries, trends displays and the status evaluation.This system is now operated in dezhou power supply company 110kV Dongfang station.