中文摘要：

针对X光机电源的全桥移相拓扑结构存在占空比丢失问题,提出一种全桥LLC串联谐振变换器与单相双向对称倍压整流电路相结合的高频高压X光机电源。在主电路中,采用全桥LLC串联谐振、高压变压器、单相双向对称倍压整流电路;从理论上分析了零电压软开关工作条件,建立主电路基波等效（fundamental harmonic approximation,FHA）模型,并对主电路的参数进行设计。仿真结果表明：输出电压可以在40～120kV内连续可调,不存在占空比丢失;输出电压上升时间短、纹波小。证明了所提出拓扑的正确性和可靠性。

英文摘要：

To prevent the duty cycle loss of full-bridge converter controlled by the phase-shifting method,a high frequency high voltage X-ray power supply is proposed.It combines full bridge LLC（FB-LLC） series resonant converter with bipolar single-phase symmetrical voltage multiplier.FB-LLC series resonant,high voltage transformer and bipolar single-phase symmetrical voltage multiplier are used in the main circuit.The LLC series resonant circuit and working conditions of soft switch are analyzed.The fundamental harmonic approximation model is established.The parameters of the main circuit are designed.The simulation results show that the output voltage adjusted continuously within 40~120 kV and without duty cycle loss.The X-ray power supply is proposed to achieve a quick rise and low ripple of output voltage.According to the simulation results,the proposed topology is correct and reliable.