基于准Z源的高增益DC-DC变换器拓扑研究

Research on topology of high-gain DC-DC converter based on quasi-Z-source

为了解决传统的DC-DC升压电路电压增益较低,以及光伏发电、风力发电等新能源输出电压低且不稳定,从而影响后级逆变等操作的问题,将准Z源网络与高增益DC-DC拓扑相结合,提出一种基于准Z源的非隔离型高增益DC-DC变换器拓扑;充分利用准Z源网络的高电压增益特性,有效解决DC-DC拓扑在升压方面的不足;为了深入研究变换器的性能,对其在连续导通模式下的拓扑结构、工作原理进行详细分析;同时基于状态空间平均法,建立变换器的小信号模型,并推导其开环传递函数。通过与其他新型拓扑的性能对比,得到该变换器不仅显著提高了电压增益,同时具有较低的开关电压应力。最后搭建仿真及实验平台来验证拓扑理论分析的正确性。

In order to solve the problems of low voltage gain in traditional DC-DC boost circuits,as well as low and unstable output voltage of new energy sources such as photovoltaic and wind power,which affect the operation of the back-stage inverter,etc.,a non-isolated high-gain DC-DC converter topology based on quasi-Z-source was proposed by combining quasi-Z-source network with high-gain DC-DC topology.The high voltage gain characteristics of the quasi-Z-source network was fully utilized to effectively solve the shortcomings of the DC-DC topology in terms of boosting.In order to conduct in-depth research on the performance of the converter,a detailed analysis was conducted on its topology and working principle in the continuous conduction mode.At the same time,based on the state-space averaging method,the small-signal model of the converter was established,and its open-loop transfer function was derived.By comparing the performance with other new topologies,it is found that this converter not only significantly improves voltage gain,but also having lower switching voltage stress.Finally,simulation and experimental platforms are built to verify the correctness of topology theory analysis.