2 kJ/s, 25 kV high frequency capacitor charging power supply using MOSFET switches

A 2 kJ/s, 25 kV (Model CCDS-225) high frequency, capacitor charging power supply combining resonant technology and pulsewidth modulation has been developed. The power supply charges a capacitor to 25 kV at a rate of 2 kJ/s, and has a regulation of <0.1% with an efficiency of >90%. The HVPS is composed of the following modules: input power rectification and filtering, series resonant inverter, high-voltage transformer and rectification, control, and inverter drive. Using state-of-the-art MOSFET or IGBT (insulated-gate bipolar transistor) switches, the series resonant inverter operates at a frequency of approximately 50 kHz. The use of MOSFETs or IGBTs allows the HVPS to use a unique pulsewidth modulation control scheme for the resonant inverter. A proprietary control scheme and the 50 kHz resonant frequency makes it possible to achieve regulation better than 0.1% for load frequencies up to 2 kHz. In addition to superior regulation for high load frequencies, this unique control approach prevents the supply from being damaged if it is accidentally operated into an open circuit. The design of the power supply is described.<>