Automatic Mode-Shifting Control Strategy With Input Voltage Feed-Forward for Full-Bridge-Boost DC–DC Converter Suitable for Wide Input Voltage Range

Abstract

Full-bridge (FB)-boost converter is suitable for applications with wide input voltage range and galvanic isolation requirement, and a two-mode phase-shift (PS)-two-edge modulation (TEM) control scheme based on two modulation signals and one carrier can be used to achieve automatic mode shifting and high efficiency. In order to reduce the influence of the input voltage disturbance on the output voltage, the small-signal model of FB-boost converter is built and the input voltage feed-forward (IVFF) functions under different operating modes are derived in this paper. In view of the small-signal and large-signal control laws of the derived IVFF functions, the two-mode PS-TEM control schemes with small-signal and large-signal IVFF compensations are proposed, respectively. Both of them can realize automatic selection of operating modes and the corresponding IVFF compensations, and thus high efficiency and improved input transient response can be guaranteed. Besides, the IVFF function in boost mode is simplified for easy implementation, and the comparisons among the two-mode PS-TEM control schemes with small-signal, large-signal, and without IVFF compensations are presented in this paper. Finally, a 250-500-V input, 360-V output, and 6-kW-rated power prototype demonstrates the effectiveness of the proposed control schemes.