一种高增益软开关直流变换器的分析与设计

在无需变压器隔离的光伏并网发电系统中，在光伏电池和并网逆变器之间须采用非隔离DC/DC变换器完成高增益变换。为此，提出了一种高增益软开关直流变换器，在相同电压增益条件下，其相对于传统升压变换器具有占空比更低、开关损耗更小、电压应力更低的优势。在分析变换器工作原理的基础上，对其性能进行了详细分析，最后搭建了一台48 V输入、380 V输出、额定功率为250 W的试验样机，实测最高效率为92.48%，实验结果验证了理论分析的正确性。

Analysis and Design of High-gain Soft-switching DC/DC Converter

In transformer-less energy systems sourced from low voltage of photovoltaic cell, the high voltage gain of the power converter is required. In this study, an high gain soft-switching DC/DC converter is discussed. The proposed converter topology offers lower duty cycle for the same voltage gain, less switching loss and lower voltage ratings of switches when compared to the basic boost converter. Analysis, design and key converter waveforms operating in the continuous conduction mode are provided. A 250 W prototype with 48 V-input and 380 V-output was built and the experimental results verify the correction of the theoretical analysis, the highest measured efficiency is about 92.48%.