| 摘要: |
| 通过在变压器副边串联LC谐振器件，在谐振频率高于2倍开关频率时，电路能实现功率MOSFET的零电压开通和零电流关断，以及副边续流二极管的零电流关断。描述了电路软开关实现的具体过程。针对副边LC谐振过程中特有的n周期谐振现象，探索了其形成机理，推导了n周期谐振下输出电压、负载电阻及谐振电容电压之间的解析公式关系，归纳得到了变换器输出电压与输出电阻、输出电流之间的特性曲线，进而阐述了电路的应用范围及设计特点。最后制作了一台实验室样机，样机最多可工作在４周期谐振模式下，对不同负载、不同周期谐振工作状态的电路波形进行测试，验证了电路工作原理。 |
| 关键词: 直流变换器 推挽电路 软开关技术 LC谐振 n周期谐振 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（51067004）；江西省科技支撑计划重点项目（2010BGA02000） |
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| Resonant push-pull DC-DC converter |
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YUAN Yisheng, GONG Changwei
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College of Electrical and Electronic Engineering，East China Jiaotong University，Nanchang 330013，China
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| Abstract: |
| By inserting the LC resonant components in series at the secondary side of transformer and when the resonant frequency is higher than the doubled switching frequency，the zero voltage turning-on and zero current turning-off of MOSFET and the zero current turning-off of freewheeling diode can be realized in push-pull converter. The soft switching process is described and the generating mechanism of the n-period resonance specially existing in secondary-side LC resonance is analyzed. The mathematic relationship between output voltage and load resistor（current） under n-period resonance is derived，the characteristic curve of output voltage vs. output current is demonstrated，and the application field and design features of the proposed converter are explained. The test of a laboratory prototype with different loads and under different period resonance modes，which can operate under up to four-period resonance mode，verifies the theoretical analysis. |
| Key words: DC-DC converters push-pull circuit soft-switching technique LC resonance n-period resonance |
