Research on ground potential of Marx generator in large current switch system

A compact Marx generator for 500 kA two-electrode spark gap switch has been designed and constructed. The Marx generator can output a pulse waveform with 30 ns rising time and 100 kV peak voltage. Then, a series of simulations and experiments have proved that the output pulse waveform of the Marx generator matches totally the project requirements of the high-current spark gas switch. On the other side, when Marx generator acts, a high-frequency and high-voltage triggering signal is generated to trigger the gap switch, and this will inevitably lead to the problem of electromagnetic interference (EMI) in power conditioning module. The issue of EMI represents a couple of aspects. Firstly, conductive coupling in the circuit will lead to ground potential rising of Marx generator shell and total module. Secondly, output current of Marx generator will produce a serious radiated interference. Based on analysis of the main circuit of the power conditioning module, a special series impedance is proposed to resolve these electromagnetic compatibility (EMC) problems. Simulations and experimental tests have proved this solution to be effective.