The Journal of Engineering (Oct 2019)
High-efficiency buck–boost converter and its control strategy suitable for wide voltage range
Abstract
In view of the need of near-space vehicle energy management system to adapt to wide input and wide output voltage range, this study presents a high-efficiency buck–boost converter and its control strategy suitable for wide voltage range. In this study, a three-mode control strategy of buck–boost circuit based on analogy circuit is proposed, which realises the smooth switching between buck–boost converter in boost, buck, and through mode. On this basis, a buck–boost power regulation unit adopting maximum power tracking algorithm control is developed. Based on the realisation of standardisation of buck–boost power conditioning unit, a power regulator is constructed by connecting two standardised units in series to achieve efficient output of power regulator in wide voltage range. In this study, the startup strategy, normal working control strategy, over-voltage and over-current protection strategy of series converter are put forward, so as to ensure the normal operation of series converter. The power regulator developed in this study is based on buck–boost topology, its output voltage is 150–300 V, and its power density reaches 2000 W/kg. The power regulator with small size, high power, high voltage, low component stress meets the need for high-power density and wide voltage range energy managers of near-spacecraft energy systems.
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