Research on input-voltage feedforward control for high-order converter topologies

The input-voltage feedforward control for the high-order converter is researched in this study. Input-voltage feedforward control can significantly reduce the audio susceptibility, that is, the input voltage to output voltage transfer function of DC-DC converter. The unified feedforward controller forms in different control modes have been derived. If the converter´s model is a high-order model, its desired feedforward controller to eliminate audio susceptibility is complex. In this study, a decomposition block diagram for high-order controller is given so the complex controller can be realised by the composition of simple controllers. When the desired controller is impossible for realisation, its proportional form can be applied to the converter to decrease the audio susceptibility in the low-frequency range. The effective frequency range is related to the main circuit parameters of the converter. The conclusions have been verified by simulation and experiment results.