Зависимость процессов в дугогасительной решетке от радиуса движущейся электрической дуги

Abstract

In electrical apparatuses containing an arc chute, arc occurs initially on the contacts arranged between the insulating walls spaced at a relatively wide distance from each other, after which the electromagnetic forces drive the arc into the area occupied by the chute plates. Electric arc is a complex phenomenon, in which a large number of physical interactions occur within a very short period of time. An analysis and calculation of arc processes in the arc quenching devices of electrical apparatuses imply simultaneous consideration of thermal gas dynamic, kinetic, electrical (network), arc, and mechanical processes. This adds much difficulty to a search of acceptable models that would satisfy all these requirements. The difficulties of solving the equations that are based on the general principles of thermodynamics and the laws of continuum mechanics are connected, in particular, with the validity of boundary and initial conditions, which are usually selected with due regard for experimental data (it should be noted that the experimental techniques in studying an arc are quite sophisticated and costly). In the course of many years, many electric arc modeling methods have been developed. The following three basic types of electric arc models should be pointed out: a physical model, a black box model, and a parametric model. These models cannot show all physical processes in an electric arc, but they can describe the variations of the main parameters. The physical processes accompanying the arc motion can slow down or even stop its displacement, which may lead to an emergency. Therefore, it is very important to select the arch chute parameters in such a way that it would offer the lowest resistance to the arc motion. In this regard, it is of primary importance to estimate the electric arc channel radius. The article is devoted to calculating the electric arc channel radius. The calculations presented in the article can be useful in selecting the parameters of arc chute plates.