Design and Control of an Electronic Bouncer Circuit for Volume-Optimal Long-Pulse High-Power Pulse Transformers

Pulse transformer size is fundamentally linked to application pulselength, pulse power and pulse rise time. In considering long-pulse high-power applications, it has earlier been demonstrated that the large voltage-time integral associated with long-pulse operation in combination with the severe pulse rise time required to ensure high pulse efficiency strictly limits the number of transformer winding turns thereby resulting in extremely large pulse transformers. This article investigates a new way of sizing and controlling an electronic bouncer circuit in reducing the effective pulse rise time. It is demonstrated that, in considering typical long-pulse application parameters, the pulse rise time may generally be reduced by a factor of 2, implying that pulse efficiency could be retained while significantly reducing pulse transformer volume. The developed idea is used in formulating a unified design procedure for volume-optimal pulse transformers with an electronic bouncer circuit. The method and proposed design procedure are illustrated and evaluated in a case study considering the European Spallation Source klystron modulator requirements (pulse amplitude of 115 kV/100 A, pulselength of 3.5 ms, pulse repetition rate of 14 Hz, and pulse rise time of
$< 120~\mu \text{s}$
). Finally, the proposed design procedure is used to evaluate the greatest attainable pulselength for a given set of application parameters and as a function of system constraints.