Numerical modeling of vacuum arc interruption based on the simplified plasma equations

The paper presents the numerical implementation of the state-variable model of the high current arc interruption. The differential equations governing the sheath development in vacuum plasma after the main frequency current zero (CZ) are coupled with the electrical circuit equations representing the power system and solved simultaneously using Advanced Continuous Simulation Language software (ACSL). The mathematical formulation of the are interruption is in the form of a black-box, i.e. the two “external” variables are voltage, u(t) and current, i(t). Other black-box variables are “internal”, i.e. they are only needed to specify the physical conditions of the arc plasma. These internal variables are: plasma density, N_io, its space distribution between contacts at CZ and its time decay due to diffusion, ion velocity, v_i, time delay between the beginning of the Transient Recovery Voltage (TRV) and CZ, t_o, and the equivalent arc diameter at current zero, D