In this paper, a control method for a 3-bridge LLC resonant converter operating with a wide output voltage control range is described. Duty changes that stem from switching devices cause topology transitions that allow the converter to shift sequentially across four operating modes, where the primary resonant tank circuits and the secondary terminals can be connected in parallel or in series making it possible to achieve a wide controllable output voltage (7.5–120 VDC). During topology mode transitions, morphing control within narrow hysteresis bands, which is achieved by varying the switching frequency and duty of the switching devices, maintains a tight regulation without noticeable output voltage transients. To verify the performance of the proposed converter, a 5-kW 700 VDC input prototype with an output voltage ranging from 7.5 to 120 VDC is built and tested.

中文翻译：

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3 桥 LLC 谐振转换器，基于拓扑变形实现宽输出电压控制范围

在本文中，描述了一种在宽输出电压控制范围内运行的 3 桥 LLC 谐振转换器的控制方法。开关器件引起的占空比变化导致拓扑转换，允许转换器在四种工作模式之间顺序转换，其中初级谐振回路和次级端子可以并联或串联连接，从而可以实现宽范围的可控输出电压(7.5–120 VDC)。在拓扑模式转换期间，通过改变开关器件的开关频率和占空比来实现窄滞后带内的变形控制，保持严格的调节，而不会出现明显的输出电压瞬变。为了验证所提出的转换器的性能，一个 5 kW 700 VDC 输入原型，输出电压范围为 7。