隔离型三绕组耦合电感交错式DC/DC变换器

讨论了四种隔离型交错式DC/DC变换器结构的特点,并在交错式Flyback变换器的基础上,引入三绕组耦合电感概念,实现了Flyback型变换器到Boost型或Buck型变换器的转换.然后,在三绕组耦合电感演绎出的一次侧并联/二次侧串联Flyback-Boost变换器上,采用有源钳位软开关电路,不仅实现了主开关管和辅助开关管的零电压软开关特性,而且只需要一组钳位软开关电路就无损地吸收了两相交错电路的漏感能量、抑制了主开关管的关断电压尖峰.三绕组耦合电感的漏感限制了输出二极管关断电流的下降速率,有效地抑制了二极管的反向恢复电流.最后,设计了一台40V输入、760V输出1kW的三绕组耦合电感实现的一次侧并联/二次侧串联交错式有源钳位软开关Flyback-Boost变换器的试验样机.实验结果验证了理论分析的正确性.

Isolated Interleaved DC/DC Converters With Winding-Cross-Coupled Inductors

Four main types of isolated interleaved structures are discussed in this paper. Then, a series of Boost or Buck type converters are derived from the conventional interleaved Flyback converter by employing winding-cross-coupled inductors (WCCIs) and interleaved structure. Furthermore, a ZVT interleaved Flyback-Boost converter with WCCIs, active clamp circuit and primary-parallel-secondary-series (PPSS) structure is analyzed as an example to explore the circuit performance. ZVT performance is realized for both the main and the clamp switches during the whole switching transition. Only one set of active clamp circuit is necessary to recycle the leakage energy and to suppress the turn-off voltage spikes. The output diode reverse-recovery problem is alleviated by the leakage inductance. A prototype with 40V-to-760V rated at 1kW has been built to verify the effectiveness of the converters.