Research on volt-ampere temperature characteristics of metal oxide surge arrester on DC line

Abstract

The operating characteristics of Metal Oxide Arrester (MOA) depend on its volt-ampere characteristics. Due to the nonlinearity of nonlinear metal oxide resistors (MOV), the volt-ampere characteristics of MOV are temperature and voltage amplitude Values, current waveforms, and many other factors. In this paper, according to the actual operating conditions of MOV, the dynamic volt-ampere characteristics at different temperatures are studied in sections to obtain the volt-ampere characteristic curve and voltage-temperature curve of MOV transient inrush current at different temperatures. The results show that: DC MOV presents a significant negative voltage temperature coefficient in the small current section, and the smaller the current value, the greater the absolute value of the negative temperature coefficient; in the operation section (30/60 us), lightning section (8/20 us), steep wave section (1/5 us) and high current section (4/10 us), the volt-ampere curve of DC MOV is not greatly affected by the ambient temperature, and the temperature coefficient of the high electric field area is not obvious; multiple lightning strikes The temperature coefficient of DC MOV has a transition from negative to positive in the operating section, and the absolute value of the temperature coefficient is very small. The maximum temperature coefficient of DC MOV is 0.0468%/℃; MOV is in the lightning section (8/20 us ) Presents a weak positive temperature coefficient, the maximum temperature coefficient of DC MOV is 0.0183%/℃; MOV presents a weak positive temperature coefficient in the steep wave region (1/5us), the maximum temperature coefficient of DC MOV is 0.0687%/℃; MOV is large The current zone (4/10us) exhibits a weak positive temperature coefficient, and the maximum temperature coefficient of DC MOV is 0.029%/℃.