Design of a high efficiency 40kV, 300us, 200Hz solid-state pulsed power modulator with long pulse width

Abstract

This paper deals with the design of a high efficiency solid-state pulsed power modulator(SSPPM) using semiconductor switches for industrial applications requiring long pulse width. Specifications of the proposed SSPPM are as follows: variable output pulse voltage, 1–40 kV; width, 1–300 us; pulse repetition rate, 1–200 pps; and average output power, 50 kW. The proposed SSPPM mainly consists of high-voltage capacitor charger and stacked switch part for applying pulse voltage to the load including a series of connected 48 pieces IGBT stack. For simultaneous charging of energy storage capacitors, a high efficiency LCC resonant inverter is proposed with multi-stage transformer and rectifier. The stacked switch part is designed based on power cell structure that has many advantages such as voltage balancing between each IGBTs, and reliable operation against synchronization failure of IGBT gate signals. In addition, a novel gate driving is proposed for fast discharging the stored energy from the capacitive load. This gate driving circuit removes pull-down resistor which induces additional power loss and achieves fast falling time. The experimental results of developed capacitor charger shows 95% and 0.96 of maximum efficiency and power factor, respectively. Finally, the performance of the proposed SSPPM is experimentally verified including rated operation, active pull-down operation, and reliable arc protection.