Model for Variable-Length Electrical Arc Plasmas Under AC Conditions.

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. [ABSTRACT FROM PUBLISHER]