This study deals with a new evaluation method of nuclear electromagnetic pulse (NEMP) vulnerability on cots electronic equipments. The method consists in comparing electromagnetic compatibility (EMC) test severiti...This study deals with a new evaluation method of nuclear electromagnetic pulse (NEMP) vulnerability on cots electronic equipments. The method consists in comparing electromagnetic compatibility (EMC) test severities to NEMP conducted stresses. The comparison uses five characteristic criteria of the induced stresses, calculated with an analytic method. The process is based on a software named "SUSIE" (in French: SUSceptibilite a I'IEMN "Impulsion ElectroMagnttique d'origine Nucl6aire Haute Altitude"). Today, only conducted stresses are analyzed. An evolution is planned in 2013 to determine the equivalent vulnerability of radiated stresses and to validate the software.展开更多
On the basis of Wilson's work in which the vertical electric dipole is centrally located in GHz Transverse ElectroMagnetic (GTEM) cell, we deduce the expression for the field distribution excited by an electric di...On the basis of Wilson's work in which the vertical electric dipole is centrally located in GHz Transverse ElectroMagnetic (GTEM) cell, we deduce the expression for the field distribution excited by an electric dipole in the case that the dipole is not centrally located. It will be useful for EMC measurements using GTEM cell.展开更多
The electromagnetic compatibility of electric vehicles is not only the important technology issue in researches,development and industrialization of electric vehicles,but also the key research area of ISO.In this pape...The electromagnetic compatibility of electric vehicles is not only the important technology issue in researches,development and industrialization of electric vehicles,but also the key research area of ISO.In this paper,both national and international standards of electromagnetic compatibility of electric vehicles are analyzed;it is also suggested that our standards of electromagnetic compatibility of electric vehicles be improved from several aspects such as testing items,test procedures,limit value,etc.The electromagnetic environment of electric vehicles is analyzed in terms of interfering sources,providing the solutions to electromagnetic compatibility and measures of reducing electromagnetic interference.Advanced equipments introduced into Chinese electromagnetic compatibility testing laboratories accelerate the pace of the researches on related technologies and standards;China will develop the standards system which covers from the complete electric vehicle to the key components,promote the technology improvement and industrialization work of Chinese electric vehicles,transform the latest achievements and advanced experiences of Chinese electric vehicles industry to the related standards and contribute the development of international standards.展开更多
It is well known that a SMPS (switched-mode power supply) is easy to produce strong EMI (electromagnetic interference) and fails in EMC (electromagnetic compatibility) test for its far field radiation exceeds th...It is well known that a SMPS (switched-mode power supply) is easy to produce strong EMI (electromagnetic interference) and fails in EMC (electromagnetic compatibility) test for its far field radiation exceeds the limits between 30-200 MHz. Based on asymmetry line antenna theory, a novel far field CM (common mode) radiation model, including an equivalent driving source, radiation structure and some key influence factors, is identified and built up for a small flyback power supply. Radiation characteristics of this model are predicted by using Ansoft HFSS software and the model effectiveness is verified by experiment. In the end, the radiation role of some key factors, such as the length of output cable, common mode impedance of AC grid, layout of cable and reflected ground, are studied using simulation in detail.展开更多
The paper presents results from a study of a series-connected single-phase APF (active power filter) with a control system based on hysteresis control, both with and without limitation of the maximum switching frequ...The paper presents results from a study of a series-connected single-phase APF (active power filter) with a control system based on hysteresis control, both with and without limitation of the maximum switching frequency. The general purpose of the series APF is to eliminate the low order harmonics of the source (grid) voltage. The filter operation at limited and unlimited maximum switching frequency is explained and it is described using building blocks and time diagrams illustrating the tracking down of the reference curve. Waveforms from the computer simulation and waveforms from the experimental tests of the filter are presented also for the two situations. Operations at limited and unlimited maximum switching frequency are compared regarding the quality of the voltage across the load, the complexity of the implementation of the control system, and the electromagnetic compatibility. The investigation proved capability of the series APF to achieve its general purpose using the hysteresis control methods studied (limited and unlimited switching frequency).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 study deals with a new evaluation method of nuclear electromagnetic pulse (NEMP) vulnerability on cots electronic equipments. The method consists in comparing electromagnetic compatibility (EMC) test severities to NEMP conducted stresses. The comparison uses five characteristic criteria of the induced stresses, calculated with an analytic method. The process is based on a software named "SUSIE" (in French: SUSceptibilite a I'IEMN "Impulsion ElectroMagnttique d'origine Nucl6aire Haute Altitude"). Today, only conducted stresses are analyzed. An evolution is planned in 2013 to determine the equivalent vulnerability of radiated stresses and to validate the software.
基金Supported by the Innovation Project of Chinese Academy of Sciences
文摘On the basis of Wilson's work in which the vertical electric dipole is centrally located in GHz Transverse ElectroMagnetic (GTEM) cell, we deduce the expression for the field distribution excited by an electric dipole in the case that the dipole is not centrally located. It will be useful for EMC measurements using GTEM cell.
文摘The electromagnetic compatibility of electric vehicles is not only the important technology issue in researches,development and industrialization of electric vehicles,but also the key research area of ISO.In this paper,both national and international standards of electromagnetic compatibility of electric vehicles are analyzed;it is also suggested that our standards of electromagnetic compatibility of electric vehicles be improved from several aspects such as testing items,test procedures,limit value,etc.The electromagnetic environment of electric vehicles is analyzed in terms of interfering sources,providing the solutions to electromagnetic compatibility and measures of reducing electromagnetic interference.Advanced equipments introduced into Chinese electromagnetic compatibility testing laboratories accelerate the pace of the researches on related technologies and standards;China will develop the standards system which covers from the complete electric vehicle to the key components,promote the technology improvement and industrialization work of Chinese electric vehicles,transform the latest achievements and advanced experiences of Chinese electric vehicles industry to the related standards and contribute the development of international standards.
文摘It is well known that a SMPS (switched-mode power supply) is easy to produce strong EMI (electromagnetic interference) and fails in EMC (electromagnetic compatibility) test for its far field radiation exceeds the limits between 30-200 MHz. Based on asymmetry line antenna theory, a novel far field CM (common mode) radiation model, including an equivalent driving source, radiation structure and some key influence factors, is identified and built up for a small flyback power supply. Radiation characteristics of this model are predicted by using Ansoft HFSS software and the model effectiveness is verified by experiment. In the end, the radiation role of some key factors, such as the length of output cable, common mode impedance of AC grid, layout of cable and reflected ground, are studied using simulation in detail.
文摘The paper presents results from a study of a series-connected single-phase APF (active power filter) with a control system based on hysteresis control, both with and without limitation of the maximum switching frequency. The general purpose of the series APF is to eliminate the low order harmonics of the source (grid) voltage. The filter operation at limited and unlimited maximum switching frequency is explained and it is described using building blocks and time diagrams illustrating the tracking down of the reference curve. Waveforms from the computer simulation and waveforms from the experimental tests of the filter are presented also for the two situations. Operations at limited and unlimited maximum switching frequency are compared regarding the quality of the voltage across the load, the complexity of the implementation of the control system, and the electromagnetic compatibility. The investigation proved capability of the series APF to achieve its general purpose using the hysteresis control methods studied (limited and unlimited switching frequency).
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.