Oxidative stability of two commercial olive oils of different specificity (green type and black type) has been studied during thermal and photochemical accelerated processes through the evolution of quality indices. I...Oxidative stability of two commercial olive oils of different specificity (green type and black type) has been studied during thermal and photochemical accelerated processes through the evolution of quality indices. It might help to assure a good utilisation of olive oil. In most of works described in literature, they are measured individually. In this study, a Principal Component Analysis (PCA) has been performed to emphasize their variation and describe in concise way the quality and the safety of extra-virgin olive oil after two oxidative stresses. No difference had been detected between both type oils when they are heated. Peroxides, aldehydes and conjugated dienes and trienes were formed but rapidly degraded into final oxidation compounds, mainly acid compounds. During the photochemical process, similar changes occurred slower and the green type oil had shown better stability because of its higher phenolic content. The fatty acids had been more impacted (higher disappearance of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA)) when the oils were heated than when irradiated. Saturated fatty acids (SFA), MUFA and PUFA were the most relevant indicators to characterize non-oxidized oils and PV characterized the early stage of oil oxidation.展开更多
SiC金属-氧化物-半导体场效应晶体管(MOSFET)作为车用电机控制器功率单元的核心器件,其并联不均流问题是影响电机控制器安全稳定运行的关键因素。对于热增强塑料封装(TPAK)SiC MOSFET功率模块实际应用中的不均流问题,首先通过理论推导...SiC金属-氧化物-半导体场效应晶体管(MOSFET)作为车用电机控制器功率单元的核心器件,其并联不均流问题是影响电机控制器安全稳定运行的关键因素。对于热增强塑料封装(TPAK)SiC MOSFET功率模块实际应用中的不均流问题,首先通过理论推导和仿真,对影响SiC并联均流的器件参数、功率回路参数、驱动回路参数进行了全面的分析总结。然后结合仿真结果对电机控制器进行均流优化设计,其中包括对TPAK SiC MOSFET进行测试、筛选和分析,减小器件参数分散性的影响;基于器件开关特性,对功率模块的驱动回路采用单驱动器多推挽结构,减小驱动回路对并联均流的影响;设计了一种叠层母排结构,在ANSYS Q3D中提取到功率回路寄生电感为9.649 nH,采用ANSYS Q3D和Simplorer进行联合双脉冲仿真,电流不均衡度小于3%。最后,进行了电机控制器样机的试制及测试,实际测试结果表明电流不均衡度小于5%,验证了在车用电机控制器应用中TPAK SiC MOSFET模块均流设计的可行性。展开更多
文摘Oxidative stability of two commercial olive oils of different specificity (green type and black type) has been studied during thermal and photochemical accelerated processes through the evolution of quality indices. It might help to assure a good utilisation of olive oil. In most of works described in literature, they are measured individually. In this study, a Principal Component Analysis (PCA) has been performed to emphasize their variation and describe in concise way the quality and the safety of extra-virgin olive oil after two oxidative stresses. No difference had been detected between both type oils when they are heated. Peroxides, aldehydes and conjugated dienes and trienes were formed but rapidly degraded into final oxidation compounds, mainly acid compounds. During the photochemical process, similar changes occurred slower and the green type oil had shown better stability because of its higher phenolic content. The fatty acids had been more impacted (higher disappearance of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA)) when the oils were heated than when irradiated. Saturated fatty acids (SFA), MUFA and PUFA were the most relevant indicators to characterize non-oxidized oils and PV characterized the early stage of oil oxidation.
文摘SiC金属-氧化物-半导体场效应晶体管(MOSFET)作为车用电机控制器功率单元的核心器件,其并联不均流问题是影响电机控制器安全稳定运行的关键因素。对于热增强塑料封装(TPAK)SiC MOSFET功率模块实际应用中的不均流问题,首先通过理论推导和仿真,对影响SiC并联均流的器件参数、功率回路参数、驱动回路参数进行了全面的分析总结。然后结合仿真结果对电机控制器进行均流优化设计,其中包括对TPAK SiC MOSFET进行测试、筛选和分析,减小器件参数分散性的影响;基于器件开关特性,对功率模块的驱动回路采用单驱动器多推挽结构,减小驱动回路对并联均流的影响;设计了一种叠层母排结构,在ANSYS Q3D中提取到功率回路寄生电感为9.649 nH,采用ANSYS Q3D和Simplorer进行联合双脉冲仿真,电流不均衡度小于3%。最后,进行了电机控制器样机的试制及测试,实际测试结果表明电流不均衡度小于5%,验证了在车用电机控制器应用中TPAK SiC MOSFET模块均流设计的可行性。