CLLC双向DC/DC变换器变死区移相控制

Variable Dead Time Phase-shifting Control of CLLC Bidirectional DC/DC Converter

针对CLLC双向DC/DC变换器反向轻载降压运行,采用固定死区时间移相控制策略时,存在金属氧化物半导体场效应晶体管(MOSFET)零电压开通(ZVS)丧失,导致效率下降的问题,提出了一种变死区时间移相控制策略。分析了CLLC反向轻载降压运行时,MOSFET的ZVS实现与死区大小和移相角度密切相关,推导了变死区时间移相控制策略的死区时间公式。试验结果表明变死区时间移相控制策略能够有效地实现CLLC反向轻载降压运行时MOSFET的ZVS,效率也高于固定死区时间移相控制策略。

Aiming at the problem of metal oxide semiconductor field effect transistor(MOSFET) zero voltage switching(ZUS) loss and converter efficiency decline when CLLC bidirectional DC/DC converter operates under reverse light load and reduction voltage,and adopts fixed dead time phase-shifting control strategy,a variable dead time phaseshifting control strategy is proposed.It is analyzed that the ZVS implementation of MOSFET is closely related to the dead time and phase-shifting angle when CLLC operates under reverse light load and reduction voltage,and the dead time formula of variable dead time phase shifting control strategy is deduced.The test results show that the variable dead time phase-shifting control strategy can effectively realize the ZVS of MOSFET under reverse light load and reduction voltage operation of CLLC,and the efficiency is higher than fixed dead time phase-shifting control strategy.