基于SiC MOSFET户用光伏逆变器的效率分析

Efficiency Analysis of Household PV Inverter Based on SiC MOSFET

户用型光伏逆变器的发展趋势是高频化、高效率、高功率密度,近年来,SiC MOSFET在电机驱动、光伏逆变器等场合得到了广泛研究。本文将SiC MOSFET应用于1.6kW两级式光伏逆变器中,提高逆变器的开关频率,对前后两级独立进行了效率分析。在前级Boost中,比较了20～100kHz开关频率下,SiC MOSFET和Si MOSFET对Boost效率的影响;在后级逆变器中,比较了100kHz SiC MOSFET逆变器与20kHz Si MOSFET H6逆变器的效率。搭建了1.6kW两级式光伏逆变器实验模型,采用SiC MOSFET,并在逆变器实验模型上对分析结果进行了实验验证。

There is a trend of higher switching frequency, higher efficiency, and higher power density in the residential PV inverters. In recent years, SiC MOSFET was well investigated in the fields of motor driving and PV inverters. In this paper, SiC MOSFET was applied in a 1.6 kW two-stage PV inverter with a high switching frequency, and the efficiencies of the two stages were analyzed. In the front-end boost, the efficiency of SiC blOSFET Boost was compared with the Si Boost when the switching frequency is changing from 20 kHz to 100 kHz. In the back-end inverter, the efficiency of al00 kHz SiC inverter is compared with that of a 20 kHz Si H6 inverter. A prototype of 1.6kW inverter is constructed and the experiment result is compared with the theoretical result.