Besides many advantages, the reduction in the operational duty of a traditional phase shifted full converter limits its scope in applications where a wide range of input voltage is the main requirement. Operation with low duty cycle extends freewheeling interval, which results in degraded performance such as more circulating current, increased conduction loss in power devices, narrow range of zero voltage switching and increased EMI. To overcome these drawbacks, this work suggests a modified phase shifted full bridge converter that keeps the operational duty of the converter high for a wide range of input voltage. This cuts the freewheeling interval and improves performance. The proposed converter consists of four low profile transformers having a structure of reconfigurable interconnections. There are two distinct reconfigurable operational modes, a low-gain mode and a high-gain mode, which can be adopted following the variation in line voltage. The proposed work is validated in LTspice simulation and hardware characterization for a wide range of input voltage 100–400 V _dc / 12 V _out and up to the load power of 1.2 kW.

中文翻译：

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一种改进的高工作占空比移相全桥转换器，可降低环流

除了许多优点之外，传统相移全转换器的工作占空比降低还限制了其在主要要求宽输入电压范围的应用中的范围。低占空比工作会延长续流间隔，从而导致性能下降，例如更大的循环电流，功率器件的传导损耗增加，零电压开关范围变窄以及EMI升高。为了克服这些缺点，这项工作提出了一种改进的相移全桥转换器，该转换器在较大的输入电压范围内都能保持较高的工作占空比。这样可以缩短续流间隔并提高性能。所提出的转换器包括四个具有可重配置互连结构的薄型变压器。有两种不同的可重配置操作模式，低增益模式和高增益模式，可随线路电压的变化而采用。提议的工作在LTspice仿真和硬件表征中得到了验证，适用于100-400 V的宽输入电压范围 _dc / 12 V _输出，最高负载功率为1.2 kW。