Multi-channel current electro-optic isolated measurement and discharge current characteristics in a parallel plate transmission line driver

Abstract

In this paper, a 96 kJ compact synchronous discharge driver is designed. The issue of the current measurement of the six parallel gas spark switches is resolved by a multi-channel isolated current measuring system, and the driver’s circuit simulation model is constructed. Then, the discharge current characteristics of each branch and load are investigated, and the results show that when the operating voltage is at least 50 kV, the parallel switches are conducted synchronously. The designed multi-channel isolated current measuring system meets the use requirements at a maximum operating voltage of 80 kV, the peak current measured by a single channel is 500 kA at this time, which corresponds to the load current of 3 MA, and the current rise time (0%–100% rise time) is about 1.15 µs. However, the asynchronous conduction of these switches will increase the branch circuit’s peak current by a maximum of 25%, and the maximum value of the inverse peak current ratio of the branch will increase to 1.16, which will threaten the safe operation of the components. At this time, there is a redistribution of charge between the already conducting branches, so the impact of the load current is less than that of the basic branch current. When the conduction dispersion of the switchers is less than 452 ns, the peak current of the load reduction is less than 3%, and the current waveform meets the application requirements. The research is essential for understanding the operating status of the driver and assessing the through-current capability of the device’s components, such as gas switches and capacitors.