Arc memory effect on postarc current in vacuum circuit breaker-simulation and experiment

Current and voltage measurements of the postarc period were carried out by means of industrial vacuum circuit breakers and a synthetic Well test circuit. The experimental results were used to determine the parameters of the sheath growth model described by J.G. Andrews and R.H. Harvey (1971). The initial ion density is fitted according to the current ramp di/dt before current zero (CZ) and according to the measured /spl int/i/spl middot/dt during the arcing phase. Two different test procedures were applied in order to separate the effect of current ramp di/dt and /spl int/i/spl middot/dt. The influence of both parameters and of the rate of rise of the recovery voltage (RRRV) on the sheath edge velocity could be demonstrated by simulation.