A Design and Analysis of RCD Oscillation Suppression Circuit for Marx Pulse Generator

Marx circuit is widely used in pulse-generating devices. However, in practical applications, the discharge loop of the Marx often includes stray capacitance and inductance, which can cause oscillations at the leading edge of the pulse. This article proposes an resistor-capacitor-diode (RCD) snubber circuit connected to the load in parallel to suppress waveform oscillations. First, the design of the RCD snubber circuit for the Marx pulse generator is presented, including the derivation of the equivalent circuit and characteristic equations. Next, the root locus method is applied to the analyzed parameters of the snubber circuit, determining the appropriate ranges of capacitance and resistance values for the RCD. Additionally, PSPICE simulation software is employed to verify the pulse oscillation suppression effectiveness of the RCD snubber circuit. Finally, the performance of the proposed RCD snubber circuit is tested on a Marx generator with 4 kV output voltage, 1 Hz frequency, and 500 ns pulsewidth. The test results demonstrate that the RCD snubber circuit has a great effect of oscillation suppression, which decreases the pules overshoot from 685 to 207 V, achieving a 69.8% reduction.