High frequency transformer is used in many applications among the Switch Mode Power Supply (SMPS), high voltage pulse power and etc can be mentioned. Regarding that the core of these transformers is often the ferrite ...High frequency transformer is used in many applications among the Switch Mode Power Supply (SMPS), high voltage pulse power and etc can be mentioned. Regarding that the core of these transformers is often the ferrite core;their functions partly depend on this core characteristic. One of the characteristics of the ferrite core is thermal behavior that should be paid attention to because it affects the transformer function and causes heat generation. In this paper, a typical high frequency transformer with ferrite core is designed and simulated in ANSYS software. Temperature rise due to winding current (Joule-heat) is considered as heat generation source for thermal behavior analysis of the transformer. In this simulation, the temperature rise and heat distribution are studied and the effects of parameters such as flux density, winding loss value, using a fan to cool the winding and core and thermal conductivity are investigated.展开更多
In order to improve the output power and increase the lifetime of laser diodes,expansion-matched submounts were investigated by finite element analysis.The submount was designed as sandwiched structure.By varying the ...In order to improve the output power and increase the lifetime of laser diodes,expansion-matched submounts were investigated by finite element analysis.The submount was designed as sandwiched structure.By varying the vertical structure and material of the middle layer,the thermal expansion behavior on the mounting surface was simulated to obtain the expansion-matched design.In addition,the thermal performance of laser diodes packaged by different submounts was compared.The numerical results showed that,changing the thickness ratio of surface copper to middle layer will lead the stress and junction temperature to the opposite direction.Thus compromise needs to be made in the design of the vertical structure.In addition,the silicon carbide（SiC） is the most promising material candidate for the middle layer among the materials discussed in this paper.The simulated results were aimed at providing guidance for the optimal design of sandwich-structure submounts.展开更多
文摘High frequency transformer is used in many applications among the Switch Mode Power Supply (SMPS), high voltage pulse power and etc can be mentioned. Regarding that the core of these transformers is often the ferrite core;their functions partly depend on this core characteristic. One of the characteristics of the ferrite core is thermal behavior that should be paid attention to because it affects the transformer function and causes heat generation. In this paper, a typical high frequency transformer with ferrite core is designed and simulated in ANSYS software. Temperature rise due to winding current (Joule-heat) is considered as heat generation source for thermal behavior analysis of the transformer. In this simulation, the temperature rise and heat distribution are studied and the effects of parameters such as flux density, winding loss value, using a fan to cool the winding and core and thermal conductivity are investigated.
文摘In order to improve the output power and increase the lifetime of laser diodes,expansion-matched submounts were investigated by finite element analysis.The submount was designed as sandwiched structure.By varying the vertical structure and material of the middle layer,the thermal expansion behavior on the mounting surface was simulated to obtain the expansion-matched design.In addition,the thermal performance of laser diodes packaged by different submounts was compared.The numerical results showed that,changing the thickness ratio of surface copper to middle layer will lead the stress and junction temperature to the opposite direction.Thus compromise needs to be made in the design of the vertical structure.In addition,the silicon carbide（SiC） is the most promising material candidate for the middle layer among the materials discussed in this paper.The simulated results were aimed at providing guidance for the optimal design of sandwich-structure submounts.
