Buck-Boost雙向變換器研究

摘要：文中對軟開關Buck-Boost雙向變換器進行了研究。根據電感電流的不同，變換器共有5種不同的工作方式。文中對電感電流過零的三種工作方式進行了詳細的原理分析。分析表明：這三種工作方式下，變換器均可實現MOS開關管的軟開關和體二極管的自然開通、關斷，無反向恢復問題。通過對48V/24V雙向變換器的設計實例，對能量雙向工作下的控制環進行的參數設計及仿真調整驗證表明，控制參數的合理選取可以使該變換器在Buck及Boost工作方式下均能穩定工作，具有實用價值。 敘詞：變換器；雙向；Buck-Boost；零電壓開關 Abstract：In the paper, research on a soft-switching bi-directional buck-boost converter is presented. The converter has 5 different operation modes when inductor current is different. The operation of three modes under the conditions that inductor current passes through zero is detailed. Analysis results reveal that under these three operation modes, the zero-voltage-switching of MOSFETs can be obtained, and the MOSFET body diodes can also be turned on and off naturally without reverse recovery problem. Finally a design example of a 48V/24V bi-directional buck-boost converter is presented. The appropriate choice of control loop parameters can make the converter stable at buck and boost operation modes respectively, and it testifies that the proposed soft-switching bi-directional buck-boost converter is practical and feasible. Keyword：Converter; Bi-directional; Buck-Boost; Zero-voltage-switching