基于拓扑组合的交错并联耦合电感高增益DC-DC变换器

针对分布式发电系统、航空航天、电动汽车等领域高电压传输比的应用场景,文章提出一种新型交错并联耦合电感高增益DC-DC变换器。所提电路结构采用拓扑组合的形式进行交错并联,一方面扩大了变换器的容量;另一方面降低了输入电流纹波。同时,当匝数比相等时,两相变换器耦合电感处理的功率相等,不存在功率失衡问题。通过集成倍压电容进一步提高了电压增益,降低了功率器件的电压应力,因此可以采用低电压等级、高性能的功率器件来提高变换器的工作效率。采用无源箝位电路吸收并利用耦合电感的漏感能量,降低了开关管的电压尖峰。此外,漏感缓解了二极管的反向恢复问题,提高了变换器的可靠性。详细地分析该变换器的工作原理、稳态性能,并搭建1000W的样机进行验证,实测最高效率为97.2%,满载效率为94.5%,实验结果验证了理论分析的正确性及所提变换器拓扑的可行性。

A High Step-up DC-DC Converter With Interleaved and Coupled Inductor Based on Topology Combination

Aiming at the application scenarios of high voltage transmission ratio in distributed generation systems, and aerospace and electric vehicles, this paper proposed a novel high step-up DC-DC converter with interleaved and coupled inductor. The proposed circuit structure adopted the form of topology combination for interleave. On the one hand, it enlarged the capacity of the converter;on the other hand, the input current ripple was reduced. Also, when the turns ratio was the same, and the power of coupled inductor of two-phase converter was equal, there was no power imbalance problem. By integrating voltage doubled capacitors, the voltage gain was further improved and the voltage stress of power devices was reduced. Therefore, low voltage level and high performance power devices could be used to improve the operating efficiency of the converter. The passive clamping circuit recycles the energy of the leakage inductor, which reduced the voltage spike of the switches. Moreover, the leakage inductor alleviated the reverse recovery problem of the diodes and improved the reliability of the converter. The operating principle and steady-state performance of the converter were analyzed in detail, and a 1000 W prototype was built for verification. The measured maximum efficiency was 97.2%, and the efficiency at full load was 94.5%. The experimental results verified the correctness of the theoretical analysis and the feasibility of proposed converter topology.