SiC特性分析仿真及其在移动储能电站的应用

The analysis and simulation of SiC and its application in mobile energy storage power station

以氮化镓(GaN)和碳化硅(SiC)为代表的第三代半导体材料由于其禁带宽度大、击穿场强高、热导率高、电子饱和漂移速度高等特性,在光电子领域及高频大功率应用上倍受青睐。本文对比了SiC和Si的物理结构和电气特性,并选取了两款MOSFETs,在实验室中用Saber仿真了它们在电路中的损耗,结果显示SiC MOSFETs平均损耗比Si MOSFETs低30%~48%。最后,讨论了SiC器件在光电子、太阳能逆变器和移动储能电站中的应用,并且在实验室中测试、分析了两台来自不同厂家的样机,实验结果显示,SiC系统比Si系统运行温度降低50%~60%,损耗降低11%,整机效率提高2.68%,功率密度由约0.46 kW/L提高到0.90 kW/L。说明SiC能够大幅提升系统的效率和功率密度,因其巨大的潜力,未来有望将工作频率提升至500 kHz以上,将系统功率密度提升至现有产品的5~10倍。

The 3^rd generation semiconductors like silicon carbide （SIC） and gallium nitride （GaN） which have wide bandgap, high breakdown voltage, high thermal conductivity and fast drift velocity are widely adopted in optoelectronics and high-frequency big-power applications. This paper briefly introduced the physical structure and electrical characteristics of SiC power semiconductors and compared these properties with that of Si power semiconductors. One SiC MOSFETs and one Si MOSFETs were chosen to compare their electrical characteristics, and they were simulated in the laboratory by Saber to compare their power loss in the same circuit. The simulation result showed that SiC MOSFETs experienced 30%--48% less power loss than Si MOSFETs. Finally, several SiC applications in optoelectronics, PV inverters and mobile energy storage power station were discussed. Two applications were tested and analyzed in detail, and the results showed that SiC system had 50%--60% lower operating temperature, 11% lower power loss, 2.68% higher efficiency and the power density had increased from 0.47 kW/L to 0.90 kW/L. It means SiC components can increase system efficiency and power density dramatically. However, SiC components still have huge potential to increase its performance, and the operation frequency can be boosted to over 500kHz. As a result, the power density of system can be 5 to 10 times greater than the current system.