三电平LLC调制策略研究

Research on Three-Level LLC Modulation Strategy

LLC谐振变换器在工程领域中已经得到十分广泛的应用,将三电平结构同LLC谐振电路相结合的三电平LLC在高压领域的应用也越来越多。三电平LLC的调制策略目前主要分为定频调制和变频调制两种,这里对各项调制策略进行了集中总结,并根据实际工程应用中的问题对变频调制策略进行了改进,进一步降低了三电平LLC中开关管损坏的风险。实验结果验证了所提调制策略的有效性。

LLC resonant converters have been widely used in the engineering field. Three-level LLC combining a threelevel structure with an LLC resonant circuit are also being used in high voltage applications.The modulation strategy of three-level LLC is mainly divided into fixed-frequency modulation and variable-frequency modulation. V arious modulation strategies are summarized and the frequency conversion modulation strategy is improved according to the problems in practical engineering applications to reduce the risk of damage to the switch tube in a three-level LLC.The experimental results verify the effectiveness of the proposed modulation strategy.