Measurement of Arc Velocity in a Rotating-Arc Pulsed-Power Switch Based on B-Dot Probes

A rotating-arc pulsed-power switch is designed in this paper. In order to realize the arc rotating characteristics, B-dot probes are installed in the switch to measure the arc velocity. Six B-dot probes are installed symmetrically in a circle under the gap to obtain the arc velocity variation with the current. The probe signal is calculated in a simplified model, and the method of velocity calculation is discussed. The theoretical errors of velocity calculation caused by the variation of arc direction are analyzed. The arc velocity is obtained from the experimental probe voltage signals using the probes in different distances, and then, the results are discussed. From the measurements, the arc rotates about 550 m/s at a current of 20 kA.