Current Detection and Control of Synchronous Rectifier in High-Frequency LLC Resonant Converter
Current Detection and Control of Synchronous Rectifier in High-Frequency LLC Resonant Converter
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高频 LLC 谐振变换器中同步整流器的电流检测与控制
DOI：
10.1109/tpel.2021.3119770
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发表时间：
2021-10
影响因子：
6.7
通讯作者：
Yang Xu
中科院分区：
文献类型：
--
作者：
Wang Kangping;Wei Gaohao;Wei Jiwen;Wu Jiarui;Wang Laili;Yang Xu
同步整流技术被广泛应用于低输出电压和大电流的应用中，以提高功率转换器的效率。然而，对于高频和大电流LLC变换器，精确控制同步整流器（SR）是具有挑战性的。本文提出了一种用于逐周期SR控制的SR电流检测方法。通过磁耦合检测谐振电流和磁化电流，然后将两者相减得到SR电流。该方法只需少量无源器件，具有带宽高、抗干扰能力强、易于实现等优点。本文详细阐述了该方法的工作原理和实现方法，并通过实验验证了该方法的有效性。该方法可应用于LLC电路的SR控制，适用于高频大电流场合。
The synchronous rectification technology is widely used to improve the efficiency of power converters in applications with low output voltage and large current. However, it is challenging to accurately control the synchronous rectifier (SR) for high-frequency and high-current LLC converters. This letter presents a method to detect the SR current for cycle-by-cycle SR control. The resonant current and the magnetizing current are detected through magnetic coupling, and then the SR current is obtained by subtracting the two. This method requires only a few passive components and has advantages, such as high bandwidth, strong anti-interference ability, and easy implementation. This letter illustrates the working principle and implementation of the proposed method in detail and then verifies the proposed method through experiments. The proposed method can be applied to SR control in an LLC circuit, suitable for high frequency and large current situations.