Development of 1 kV, 30 kW Capacitor Charging Power Supply of Solid-State Pulse Modulator

This paper reports the development of 1 kV, 30 kW capacitor charging power supply of solid-state pulse modulator. It provides variable output voltage 300–1000 V and maximum current up to 30A depending on load. The power supply design is based on DC-DC series resonant converter. High-frequency transformer’s leakage inductance is utilized in resonant circuit to achieve zero switching losses. In view of switching current (125APeak) and switching voltage (1.2kVPeak) at resonating frequency of 100 kHz in the resonant circuit, low loss metalized polypropylene film capacitors are required. A variable switching frequency controller has been implemented to maintain the output load voltage at the specified DC level. With these considerations, 1 kV, 30 kW capacitor charging power supply has been designed, simulated and developed. It is assembled in the standard 19-inch, 6U electronics rack. Development of resonant converter-based power supply leads to compact size, easily controllable, low cost, highly efficient (≥95%) and precise output voltage regulation (±1%). Also, high-frequency (100 kHz) sinusoidal-current envelope significantly contributes in the mitigation of harmonics as well as EMI. The main advantage of this power supply is its ability to operate under short-circuit to open-circuit conditions, thus improving reliability of the overall system. The developed power supply has been tested on the simulated load. Subsequently, it was integrated with solid-state pulse modulator. The supply charges energy storage capacitors of pulse modulator up to 1 kV with 25A maximum charging current. The maximum operating charge/discharge cycle is 220 per second. 30 kW power supply was developed and deployed. Its design and test results are presented in this paper.