High efficiency and reliability pulsed power system for medical lasers with the digital controller

This research presents an optimal design of a phase shift full bridge (PSFB) converter with a proposed constant power (CP) charge mode for capacitor charging power supply (CCPS). Three pieces of PSFB transformer are connected in series at the output to overcome the high voltage stress for each component as well as in parallel at the input for sharing the large current. The proposed converter is designed to achieve soft switching at all the switches and to charge the capacitor by a CP mode during the nominal working conditions thereby improving the system efficiency as well as minimizing the charge time for the capacitor. The operation principle is detailed and performance of the proposed converter is verified by implementing a 5kW prototype. The experimental results show that the peak efficiency of the converter is 97.5% and the charge time is 15% faster compared with constant current charge mode at the same converter power rating.