The structure of a DC–DC converter connected in series with a 400 Hz inverter is widely used in aviation airborne and ground power systems to provide a medium-frequency AC power supply within a wide input voltage range. To guarantee the dynamic and steady-state performance of a multi-module series converter, it is necessary to individually optimize the control loop and the parameters of each series-connected module. In addition, it is also necessary to consider the input–output impedance matching issues of each converter. In this study, a phase-shifted full-bridge converter employing an average current control strategy is used as the input-side DC–DC converter, and a medium-frequency three-phase four-leg inverter is used as the output-side inverter. The study also conducts a small-signal modeling analysis to reveal the intrinsic relationship between the closed-loop output impedance of the input-side converter and the circuit parameters. It summarizes the optimization criteria for controlling the parameters of the voltage and current loops. By suppressing the peaks of the output impedance of the input-side converter, the impedance matching between the input- and output-side converters is ensured over the entire frequency range, ensuring the stable operation of the overall system. Finally, the correctness of the theoretical analysis is verified through simulation and experimentation.

DC-DC变换器与400Hz逆变器串联的结构广泛应用于航空机载和地面电源系统，以在较宽的输入电压范围内提供中频交流电源。为了保证多模块串联变换器的动态和稳态性能，需要单独优化控制回路和每个串联模块的参数。此外，还需要考虑各个转换器的输入输出阻抗匹配问题。在本研究中，采用平均电流控制策略的移相全桥变换器用作输入侧DC-DC变换器，中频三相四桥臂逆变器用作输出侧逆变器。该研究还进行了小信号建模分析，以揭示输入侧转换器的闭环输出阻抗与电路参数之间的内在关系。它总结了控制电压和电流环路参数的优化标准。通过抑制输入侧变换器输出阻抗的峰值，保证输入侧变换器与输出侧变换器在整个频率范围内的阻抗匹配，保证整个系统的稳定运行。最后通过仿真和实验验证了理论分析的正确性。