三电平Boost变换器在光伏系统MPPT中的应用

Application of Three-level Boost Converter in MPPT of Photovoltaic System

介绍了三电平升压Boost变换器在光伏发电系统最大功率点跟踪MPPT中的研究与实现。三电平Boost变换器与传统方法不同的是,前者通过精确的相移控制实现输出电容电压的平衡。文中采用扰动观察MPPT算法跟踪不同辐照度条件下的最大电压。三电平Boost变换器在宽输入范围电压为470~700 V时,输出电压、输出功率能够分别达到750 V和5 k W。采用数字信号处理器TMS320F28035控制MPPT。仿真结果表明,该系统的效率可达98%,MPPT平均精度可达98.6%。

This paper introduces the research and implementation of three-level boost converter in maximum power point tracking（MPPT）. The characteristics of this converter include the high voltage application requires low voltage application requires low voltage application requires low voltage stress,small inductor size that leads to the reduction of cost and size and can work under a wide range of input voltage. Different from the traditional method,the output capacitance voltage is balanced by a precise phase shift control. Perturbation and observation MPPT method is used to track the maximum voltage under different irradiation conditions. A 5 k W three-level boost converter with a wide range input voltage from 470 V to 700 V and a high output voltage of 750 V is realized. The MPPT control is implemented with a digital signal processor TMS320 F28035. The simulation results show that the efficiency of the system can reach to 98% and the MPPT average precision reaches 98.6%.