Design of 20kJ/s compact high voltage capacitor chargers for pulsed power application

Summary form only given. This paper describes the design and the implementation of a 20kJ/s resonant converter based compact high-voltage capacitor chargers with two different transformers and rectifiers structure in order to provide a variety of maximum output voltage. Series-parallel resonant converter (SPRC) based resonant inverter allows not only high-power density but also high-efficiency owing to the high-frequency operation with soft-switching at turn-on as well as turn-off transition. In addition, the capacitors which are used for balancing the voltage across each diode for highvoltage rectifier were designed to shape the resonant current as trapezoidal and it provides less conduction loss compared to the sinusoidal waveform. Based on a novel structure of resonant inverter, two kinds of high-voltage transformers and rectifiers are designed for 10kV and 40kV maximum output voltage specifications, respectively. With the considerations of the insulation in the air, the implementation of highvoltage part for 10 kV output such as transformer bobbin and rectifier circuit is explained. For the 40 kV charger, otherwise usually requires oil insulation, a detailed design of the highvoltage parts including oil box, transformer, rectifier, and cooling structure is provided. Furthermore, the design of transformer with two secondary windings facilitates a variety of maximum output voltage as 5 kV, 10 kV, 20 kV, 40 kV with 20 kJ/s average charging power by simple modification of rectifier connection. A detailed design and implementation procedure as well as experimental results which were carried out with various kinds of load are discussed in the following paper.