This paper presents and investigates planar and coaxial high frequency power transformers used for DC/DC converters in a three phase photo voltaic （PV） power systems. The winding structure including a Faraday shield...This paper presents and investigates planar and coaxial high frequency power transformers used for DC/DC converters in a three phase photo voltaic （PV） power systems. The winding structure including a Faraday shield between the primary and secondary windings is designed to minimize eddy current losses, skin and proximity effects, and to reduce the leakage inductance, and the inter winding coupling capacitance. Finite Element Method is employed to analyze the magnetic flux and eddy current distributions. The two different kinds of prototype high frequency transformers are designed and tested. The simulation and experiment results are demonstrated and compared with non-shielded transformers. The shielded transformers have achieved the expected results with a relatively small coupling capacitance, compared with the conventional high frequency transformer. This shield decreases the inter-winding coupling capacitance Cps. The topology of this shield has to be such that it acts as a Faraday screen while avoiding eddy current generation.展开更多
In order to fulfill the ever-growing requirements for electromagnetic interference(EMI)shielding materials,achieving a high efficiency with great flexibility is still a big challenge.Herein,high-performance EMI shield...In order to fulfill the ever-growing requirements for electromagnetic interference(EMI)shielding materials,achieving a high efficiency with great flexibility is still a big challenge.Herein,high-performance EMI shielding composite films with excellent mechanical properties were fabricated via a convenient evaporation method using poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)and silver nanowires(Ag NWs)as conductive fillers.By adding 1.38 wt% Ag NWs into the original polyvinyl alcohol/PEDOT:PSS(PVA/PEDOT:PSS)composite,the obtained film with a thickness of about 20μm shows a remarkable EMI shielding performance(~33 dB)and a special EMI shielding efficiency of 16,800 dB cm^(-1) at 10 GHz.Furthermore,PVA/PEDOT:PSS/Ag NWs films present excellent tensile strength(~62.39 MPa)and elongation at break(~29.3%).The good mechanism allows the films to apply in actual harsh environments.Overall,this study will draw attention to the new films for electromagnetic shielding application.展开更多
文摘This paper presents and investigates planar and coaxial high frequency power transformers used for DC/DC converters in a three phase photo voltaic （PV） power systems. The winding structure including a Faraday shield between the primary and secondary windings is designed to minimize eddy current losses, skin and proximity effects, and to reduce the leakage inductance, and the inter winding coupling capacitance. Finite Element Method is employed to analyze the magnetic flux and eddy current distributions. The two different kinds of prototype high frequency transformers are designed and tested. The simulation and experiment results are demonstrated and compared with non-shielded transformers. The shielded transformers have achieved the expected results with a relatively small coupling capacitance, compared with the conventional high frequency transformer. This shield decreases the inter-winding coupling capacitance Cps. The topology of this shield has to be such that it acts as a Faraday screen while avoiding eddy current generation.
基金supported by the National Nature Science Foundation of China(51971111)the Postgraduate Research&Practice Innovation of Jiangsu Province(KYCX200190)Jiangsu Provincial Key Laboratory of Bionic Functional Materials。
文摘In order to fulfill the ever-growing requirements for electromagnetic interference(EMI)shielding materials,achieving a high efficiency with great flexibility is still a big challenge.Herein,high-performance EMI shielding composite films with excellent mechanical properties were fabricated via a convenient evaporation method using poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)and silver nanowires(Ag NWs)as conductive fillers.By adding 1.38 wt% Ag NWs into the original polyvinyl alcohol/PEDOT:PSS(PVA/PEDOT:PSS)composite,the obtained film with a thickness of about 20μm shows a remarkable EMI shielding performance(~33 dB)and a special EMI shielding efficiency of 16,800 dB cm^(-1) at 10 GHz.Furthermore,PVA/PEDOT:PSS/Ag NWs films present excellent tensile strength(~62.39 MPa)and elongation at break(~29.3%).The good mechanism allows the films to apply in actual harsh environments.Overall,this study will draw attention to the new films for electromagnetic shielding application.
