Plasma characteristics of medium voltage AC air arc discharge and its application on arc electrical parameters calculation

Abstract

Medium Voltage (MV) AC air arcs occur frequently in distribution networks. An electric arc can easily cause electrical fires, leading to serious accident consequences. Obtaining the electrical characteristics of arc faults through arc models is a crucial measure to detect and prevent arc faults. The arc electrical characteristics are affected by many factors such as the ambient air pressure, current magnitude, and arc length, and it is difficult to describe it in an analytical form. The widely used conventional black-box arc model reflects the influence of multiple factors on the electrical characteristics of arcs through fitting or empirical formulae. The model ignores the intrinsic physical and chemical processes, and the applicable range of the model is limited. Focusing on this problem, based on the physicochemical processes of the arc in the arcing and post-arcing stages, a relationship between the electrical and plasma characteristics of the MV AC air arc was established. Subsequently, the arc plasma characteristics were determined experimentally, and were applied to the calculation of the arc electric characteristics. Finally, the calculation results of the arc electrical characteristics were verified using the experimental results, providing a basis for related model improvements and applications.

Measurement of medium-voltage AC air arc temperature and particle number density based on dual-wavelength Moiré deflection technology

“…The arc generating circuit consists of the B-phase line of the 10 kV three-phase power supply, circuit resistance and the earth. The detailed parameters of the 10 kV three-phase power system can be found in our previous work [33]. The phase voltage was 6 kV (root-mean-square value), and the circuit resistance was set to 5 kΩ.…”

“…According to our previous work, the term of p loss term is related to the arc temperature, particle density and the transport coefficient [33]. Therefore, the non-LTE arc mathematical model can be solved based on the measured particle density and temperature of this paper.…”