Research On High Performance Single Phase Dual Stage DC-AC Intermediate Frequency Converter

400Hz/115V AC is widely used in aerospace,ships,radar and other special areas.Power density,power level,waveform quality,efficiency and reliability are very important quotas.In this paper,a high power density and high reliability lkVA intermediate frequency converter is designed to meet the expected requirements.The converter employs two-stage structure:the pre-stage uses DC-DC converter to realize isolation and voltage boosting.The post-stage adopts the full bridge topology as the inverter structure.Firstly,this paper analyses the converter input and output electrical requirements and adopts IPOS phase-shifted full-bridge as the pre-stage converter.The IPOS structure can reduce the current stress of power switches,transformer and filter volume.Then the paper introduces the structure of DC-DC converter,the suppression strategy of the secondary current ripple from the inverter.Then the inverter control strategy and control method with nonlinear loads are presented.Secondly,this paper designs the electrical parameters and the control algorithm of DC-DC converter.The notch filter is added in the voltage feedback loop to suppress the secondary current ripple.The improved load current feedforward mode is used to improve the dynamic response speed.Then the master-slave control method is proposed to achieve the power sharing and fast voltage stabilization.Then the control parameters are designed and the feasibility of the design is verified by simulation.Thirdly,this paper designs the electrical parameters and the control algorithm of the inverter part.,an improved load current feedforward double closed loop control method based on PR is designed.Aiming at the nonlinear load,the repetitive control combined with the resonant controller method and the multi resonance controller method are designed to compensate the harmonic current.Then the control parameters are designed,and the feasibility of the design is verified by simulation.Finally,the prototype of the two-stage converter of lkVA is set up,and the hardware circuit is introduced.The experimental data verify the correctness and feasibility of the theoretical design.