Vacuum arc characters research on DC forcing interruption

In this paper, the characters of the vacuum arc parameters in 270V DC forcing interruption were investigated. In which we considered some factors, such as the forcing frequency, the rate of the current and voltage at zero passage (di/dt, dv/dt), the charging voltage of the commutation circuit capacity, and the current magnitude. The experiment was performed on a synthetic test circuit, which composed by the RC main current circuit, LC commutation circuit and a cup type AMF contactor, which electrodes´ diameter is 66mm, and gap is 4mm and a plane one for miniaturization use. The experiment showed that with the forcing frequency increases (2.3 kHz, 3.1 kHz, and 4.2 kHz) and other factors the same, the forcing arc duration decreased obviously, and the rate of the di/dt raised. Meanwhile the peak of the arc overvoltage raise, the voltage noise get smooth, and the inverse arc current peak increase. In other experiments, we fixed the di/dt. Under the same circuit parameters, the current magnitude influenced the current and voltage peak value, And the charging voltage determine the arc duration. 3 types waveform for the failure interruption, and the di/dt-dv/dt characteristics was investigated. And finally compare the obviously difference of post-arc current between AMF and plane VI, The knowledge may guides us to optimize a smaller apparatus for utility use.