High-voltage and high-current crowbar system based on pseudospark switches: from system design to verification

Abstract

This paper presents a high-voltage and high-current crowbar system using pseudospark switches to produce a fast front edge and prolonged pulse current with low ripple amplitude. The crowbar system mainly consists of a main switch, a crowbar switch, an energy storage capacitor, and an inductive load. The basic parameters of the pseudospark switch crowbar system: the storage capacitance is 5 μF, the typical operation voltage is 30 kV, the peak discharge current is about 46.2 kA, the rise time is 4.3 μs, and the pulse duration time is approximately 109 μs, which is nearly 25 times of the rise time. In this paper, we report the timing setting for crowbar system. Experimental results show that crowbar timing should be set slightly after first current maximum, which has a great advantage of increasing the time scale without any reduction in the loss-free peak current. In addition, the pulse current characteristics are also studied. In the research, crowbar inductance Lc and crowbar resistance Rc have significant effects on the ripple amplitude and load current amplitude of pulse current. The experimental results also show that the crowbar current Ic can reach nearly twice of the coil load current Iload with low crowbar inductance Lc. The over-current capacity of the crowbar switch needs to be greater than that of the main switch. The experimental results in this paper can be used to optimize the inductive load current in high-voltage and high-current crowbar system.