Considering the shortcomings of two-stage photovoltaic grid-connected power generation system,such as higher voltage stress and higher inductance current of power device in the traditional BOOST circuit and the insufficient voltage gain,a novel high-gain DC-DC BOOST converter is proposed in this paper. Its working principle and three opera?tion modes under the conditions of continuous/discontinuous inductance current are introduced,and the voltage gain and external characteristic curve are also given. Moreover,the proposed converter is compared with some traditional BOOST circuits from the aspects of voltage gain,voltage stress of the switch tubeand inductance current stress. Finally, an experimental prototype rated at 200 W was built,which verified the corresponding theoretic alanalysis .%针对两级光伏并网发电系统中传统BOOST电路功率器件电压应力和电感电流较大,电压增益不足等缺点,本文提出了一种新型的高增益直流升压变换器.文中详细介绍了该新型变换器的工作原理和其在电感电流连续及断续条件下的3种工作模态,并通过推导给出了电压增益及其外特性曲线.将一些常见的升压电路在电压增益、开关管电压应力、电感电流应力等方面与本文方法进行了比较.最终通过搭建的输出功率为200 W的实验样机,证明了理论分析的正确性.
展开▼
