Charging High Voltage capacitors in pulsed power applications with a Capacitor Diode Voltage Multiplier of reduced size and lower ripple currents

摘要

The Cockroft-Walton multiplier is an established converter to generate high voltage, that can be used to charge capacitors for pulsed power applications. In this paper the drawbacks for this use case are shown and with the Two Phase Capacitor Diode Voltage Multiplier Type A a promising alternative solution is presented. While this topology seems to be the less obvious choice between both converters under steady state conditions, it shows its strength at repetitive capacitor charging. One of the benefits is a great reduction of the ripple currents overlayed to the desired constant DC current, by reducing reverse flowing charges and doubling the output frequency. Thus the pre-resistor for diode protection has lower losses or could be increased to improve the robustness. Filtering on the current measurement becomes simpler and disturbances are easier to avoid. The capacitor values can be greatly downscaled leading to reduced weight, size and cost. With smaller values, the power supply requirements are lowered, since the multipliers capacitance acts as an additional load to it. The reduction of energy stored inside the multiplier by a factor of 17 enhances the efficiency.