適用于混合動力汽車的DC/DC變換器低損耗控制方法

摘要：提出了一種雙向級聯升降壓變換器的低損耗、恒頻、零電壓開關的控制方法 ，可應用于混合動力汽車中。通過和傳統控制方法對比，討論了其優點和軟開關解決方案。在這種控制方法下，每個脈沖周期的開始和結束時，產生一個負向的偏置電流，使開關器件導通，這樣MOSFET開關管就可在反向并聯二極管導通時開通。由于這種控制方法是純軟件解決方案，與傳統控制方法相比，更具有成本優勢。該模型的工作理論和軟開關的工作過程，通過變換器樣機進行了實驗驗證。 敘詞：零點壓開關 雙向級聯 混合動力汽車 直流變換器 Abstract：A low-loss, constant-frequency, zero-voltage-switching (ZVS) modulation strategy for bi-directional cascaded, buck-boost DC/DC converters, used in a hybrid electrical vehicle (HEV), is presented and its benefits over state-of-the-art converters and soft-switching solutions are discussed in a comparative evaluation. With the purposed modulation strategy, the switches are gated in a way that the inductor current has a negative offset current at the beginning and the end of each pulse period. This allows the MOSFET switches to turn on when the anti-parallel body diode is conducting. As the novel modulation strategy is a software-only solution, there are no additional expenses for active or passive components compared to conventional modulation implementations. Experimental measurements performed with a converter prototype verify the mode of operation and the ZVS principle. Keyword：ZVS, Bi-directional cascaded, HEV, DC/DC Converter