Quality Assessment of Low Voltage Surge Arresters

Abstract

Users expect reliable operation of the surge arrester during overvoltages, which may originate from a switching process or a lightning discharge. The necessary conditions to guarantee these expectations are: appropriate construction of the surge arrester, its production being maintained in accordance with technical standards, and a positive results of the type test. The recipient, especially when purchasing large quantities of the product, can check the final quality of the product through selective testing of samples from the market in order to find the best supplier. This manuscript specifies the basic parameters of low-voltage (LV) surge arresters of four manufacturers. Basic electrical parameters, i.e. leakage current and reference voltage before and after the discharge current of 8 µs /20 µs, were determined for 10 randomly selected surge arresters of each manufacturer. Moreover one sample of each varistor batches was aged by 50 simulated lightning strikes. The obtained results of structural analysis indicate that the crystal structure of the varistor materials changes after ageing process, affecting its electrical properties. The proposed research methodology can be employed as a basis for forecasting the stability of the arrester parameters under operating conditions.

A Bibliometric and Comprehensive Review on Condition Monitoring of Metal Oxide Surge Arresters

“…Izoulet et al [ 89 ] and Simo et al [ 90 ] both made improvements to the manufacturing process of the varistor blocks that allowed increases in the nonlinearity coefficient of the ZnO blocks and a reduction in the leakage current. Also, in their work, Litzbarski et al [ 37 ], combined measurements of electrical parameters and physicochemical tests in order to measure the repeatability in the fabrication process of ZnO varistors, for production quality purposes.…”

“…Differences in grain size, spinel precipitations and pores result in weaknesses in the microstructure [ 36 ]. According to [ 37 ], the conduction of elevated surge currents causes shrinkage of ZnO grains and modification of grain boundaries, affecting the electric parameters. Usually, the methods used to analyze the microstructure are destructive methods, requiring the sample to be disassembled.…”

Leakage Current Measurements of Surge Arresters

“…Regardless of the numerous advantages of ZnO-based varistors, the impact of overvoltage often causes varying failures of these devices [20]. The repeated lightning strokes lead to the degradation of the structure of metal oxide surge arresters and, in consequence, deteriorate their electrical parameters [21]. For this reason, it is necessary to assess the technical condition of these devices.…”