Three-region frequency control scheme for series resonant converter based X-ray power supply

The output voltage profile of a high-voltage power supply for a medical X-ray generator needs to possess a quick rise time with negligible overshoot and minimum high-frequency ripple. With soft switching, it is challenging to meet this requirement in high-voltage DC power supplies under varying load settings and output voltages. In this work, a three-region frequency control scheme is proposed for a series resonant converter with multi-stage voltage multiplier based high-voltage power supplies. A step-changed frequency control, based on the output voltage profile with zero voltage switching is described. A 32.5 kW, 75 kV high-voltage power supply composed of a series resonant converter, a high-voltage transformer, and two sets of 4-stage voltage multiplier is designed and simulated with PSIM software. The effectiveness of the proposed three-region frequency control scheme is validated with steady-state and transient response simulation results.