A Solid-State Converter Topology, −100 kV, 20 A, 1.6 ms, Modulator for High Average Power Klystron Amplifier

Abstract

This paper presents the design and development of a −100 kV, 20 A, all solid-state long-pulse modulator for driving high average power klystron amplifier. Modular design approach has been adopted for achieving the −100-kV output. Six dc–dc converters along with high-voltage high-frequency transformers are used for high-voltage generation. Low-loss insulated gate bipolar transistor (IGBT) switches in full-bridge configuration have been used for high-frequency switching. The IGBT-based inverter modules are delayed in phase by 120° with respect to each other. The switching frequency is 20 kHz. Output pulses of 1.6-ms pulsewidth, 70- $\mu \text{s}$ rise time, and 65- $\mu \text{s}$ fall time have been achieved at the modulator output. A droop of ±1% is achieved using a simple feedforward correction control technique. The performance of the modulator with the resistive load is presented.