Model for Variable-Length Electrical Arc Plasmas Under AC Conditions

Abstract

This paper proposes a mathematical model for electrical discharge plasmas between moving electrodes under ac condition, which happens in ac switching apparatuses. The modeling work is started by converting the problem to a conventional RL network that treats the arcing phenomenon as a black box and proposing a transient differential equation to represent the breaking arc process. A resistance-time relation model developed from the classic Mayr model is then proposed. A conceptual unit-arc approach is used to deal with the issue of variable arc length as the contacts move. Experimental data from ac contactor tests are used to approximate the resistance-time function by a nonlinear curve fitting. The model is solved computationally and compared with the experimental data. It is that the model adequately describes the breaking arc phenomenon. . His current research interests include data analysis on electrical apparatus, including arc modeling, reliability, endurance prediction, fault detection, electric automatization and intellectualization, including applications of automatic and intelligent manufacturing, and industrial image processing.Guichu Wu is currently the Director of the

Effects of Fast Elongation on Switching Arcs Characteristics in Fast Air Switches

“…A mathematical model is presented for variable-length AC arcs in contactors with elongating speeds of about 1 m/s, where the arc voltage is described by a series arc concept [25]. It is only applicable to cylindrical arcs when the temperature distribution is radial homogenous.…”

The Electrical Behaviour of Railway Pantograph Arcs

“…Various approaches have been proposed to provide a dynamic model able to comprehend both low-and high-current behaviour, including detailed dynamics and losses, depending on the relevance of each quantity for the specific application: besides the electric arc from a sliding contact considered here, there are in addition current interruption, welding and plasma torch for melting and pyrolisis, to cite the most diffused applications [68]. So, more complex arc models have been investigated, mostly by combining different elementary arc models for different arc current amplitude intervals (called "series subarcs" in [69]), rather than forcing one arc conductance-energy model to fit all operating points. In particular, much different temperatures or atmospheres have justified the adoption of slightly different assumptions, resulting in some other models and variants applicable e.g., to gliding discharge scenarios [70] and variable plasma column length e.g., for current interruption applications [71], that are appended at the end of the Section.…”

“…In [69] the cooling power P 0 is linearly proportional to the arc length, including dynamic scenarios where the arc length is subject to change during e.g., circuit breaker opening.…”