EMI Filter Design and Performance for isolated full bridge buck converter is developed in this paper. In order to design a high performance EMI filter, many issues need to be considered beforehand. Some important issu...EMI Filter Design and Performance for isolated full bridge buck converter is developed in this paper. In order to design a high performance EMI filter, many issues need to be considered beforehand. Some important issues including accurate model of converter components, parasitic elements, its effect on EMI noise and impedance mismatch are included in this paper. A numerical prediction of EMI/EMC has the potential to evaluate EMI performances at the design stage and before prototyping. It can also help reduce the post-prototype EMC cost by minimizing late redesign and modifications of a design implementation. Saber simulator is used to analyze the EMI noises and EMI filter’s performance. Conducted EMI noise measurement and EMI filter design of isolated full bridge buck converter has been achieved while successfully satisfying the FCC class B limits in the frequency range from 150 kHz to 30 MHz. Simulation results are compared with experimental data and the effectiveness of the EMI simulation approach is demonstrated.展开更多
This paper introduces a design of high-precision high-voltage fiber-optic analog sig-nal isolation converter based on the technology of Voltage-to-Frequency (V/F) and Frequency-to-Voltage (F/V) conversion. It describe...This paper introduces a design of high-precision high-voltage fiber-optic analog sig-nal isolation converter based on the technology of Voltage-to-Frequency (V/F) and Frequency-to-Voltage (F/V) conversion. It describes the principle, system configuration and hardware design.展开更多
DC–DC converters have achieved great popularity in recent decades due to their immense penetration in various applications.With this motivation,the authors have conducted a thorough review of recent advancements in v...DC–DC converters have achieved great popularity in recent decades due to their immense penetration in various applications.With this motivation,the authors have conducted a thorough review of recent advancements in various topologies of DC–DC converters.The need for DC power has raised further for certain applications like grid integration of distributed generation(DG),solar photovoltaic(PV),wind power generation(WPG),fuel cells(FC),etc.The investigation of converter topology is performed to achieve the desired objective of a specific application.Like in a PV system,to obtain the inherent capability of a DC–DC converter for operating at the maximum power point(MPP)and thereby electronically extracting the maximum power from the source.Hence,a detailed review of topological advancements on the low to medium-voltage and medium-to-high-power DC–DC converters has been carried out.Moreover,a thorough investigation has been carried out on profuse closed-loop strategies and compared with each other for obtaining the optimum or maximum output performance and thereby obtaining the utmost source utilization.The modern control techniques though have relatively more calculation time but,they tend to reduce the steady-state error that leads to the stabilization of the converter.Lastly,certain applications of the DC–DC converters have been explained to get an overall idea of the usefulness of such power converters.展开更多
In today’s fast-paced,information-driven world,data centers can offer high-speed,intricate capabilities on a larger scale owing to the ever-growing demand for networks and information systems.Because data centers pro...In today’s fast-paced,information-driven world,data centers can offer high-speed,intricate capabilities on a larger scale owing to the ever-growing demand for networks and information systems.Because data centers process and transmit information,stability and reliability are important.Data center power supply architectures rely heavily on isolated bidirectional DC-DC converters to ensure safety and stability.For the smooth operation of a data center,the power supply must be reliable and uninterrupted.In this study,we summarize the basic principle,topology,switch conversion strategy,and control technology of the existing isolated bidirectional DC-DC converters.Subsequently,existing research results and problems with isolated bidirectional DC-DC converters are reviewed.Finally,future trends in the development of isolated bidirectional DC-DC converters for data centers are presented,which offer valuable insights for solving engineering obstacles and future research directions in the field.展开更多
This paper presents an isolated DC/AC/DC converter using a middle frequency transformer coupling two modular multilevel converters(MMC),suitable for interconnecting DC transmission lines of different voltage levels in...This paper presents an isolated DC/AC/DC converter using a middle frequency transformer coupling two modular multilevel converters(MMC),suitable for interconnecting DC transmission lines of different voltage levels in high voltage direct current(HVDC)system.The basic operational principle of the isolated module multilevel DC/DC converter(IMMDCC)is analyzed.The dynamic model of IMMDCC is studied in detail and the transient relationship between DC side and AC side of IMMDCC is revealed,which is physically straightforward for understanding the power transfer in IMMDCC.The control strategy in D-Q coordinate system is put forward,and the fault characteristic and corresponding protection method is analyzed.Finally,computer simulation using Matlab/Simulink is performed to verify the dynamic model and the proposed control strategy.The simulation results show good performances and the quick response ability of the proposed control strategy.展开更多
Three angiotensin I converting enzyme(ACE) inhibition peptides were isolated from sandworm Sipunculus nudus protein hydrolysate prepared using protamex. Consecutive purification methods, including size exclusion chrom...Three angiotensin I converting enzyme(ACE) inhibition peptides were isolated from sandworm Sipunculus nudus protein hydrolysate prepared using protamex. Consecutive purification methods, including size exclusion chromatography and reverse-phase high performance liquid chromatography(RP-HPLC), were used to isolate the ACE inhibition peptides. The amino acid sequences of the peptides were identified as Ile-Asn-Asp, Val-Glu-Pro-Gly and Leu-Ala-Asp-Glu-Phe. The IC_(50) values of the purified peptides for ACE inhibition activity were 34.72 μmol L^(-1), 20.55 μmol L^(-1) and 22.77 μmol L^(-1), respectively. These results suggested that S. nudus proteins contain specific peptides that can be released by enzymatic hydrolysis. This study may provide an experimental basis for further systematic research, rational development and clinical utilization of sandworm resources.展开更多
基金Sponsored by the National Science Foundation of China (Grant No.50477009).
文摘EMI Filter Design and Performance for isolated full bridge buck converter is developed in this paper. In order to design a high performance EMI filter, many issues need to be considered beforehand. Some important issues including accurate model of converter components, parasitic elements, its effect on EMI noise and impedance mismatch are included in this paper. A numerical prediction of EMI/EMC has the potential to evaluate EMI performances at the design stage and before prototyping. It can also help reduce the post-prototype EMC cost by minimizing late redesign and modifications of a design implementation. Saber simulator is used to analyze the EMI noises and EMI filter’s performance. Conducted EMI noise measurement and EMI filter design of isolated full bridge buck converter has been achieved while successfully satisfying the FCC class B limits in the frequency range from 150 kHz to 30 MHz. Simulation results are compared with experimental data and the effectiveness of the EMI simulation approach is demonstrated.
基金This work was supported by the National Meg-Science Engineering Project of the Chinese Government.
文摘This paper introduces a design of high-precision high-voltage fiber-optic analog sig-nal isolation converter based on the technology of Voltage-to-Frequency (V/F) and Frequency-to-Voltage (F/V) conversion. It describes the principle, system configuration and hardware design.
文摘DC–DC converters have achieved great popularity in recent decades due to their immense penetration in various applications.With this motivation,the authors have conducted a thorough review of recent advancements in various topologies of DC–DC converters.The need for DC power has raised further for certain applications like grid integration of distributed generation(DG),solar photovoltaic(PV),wind power generation(WPG),fuel cells(FC),etc.The investigation of converter topology is performed to achieve the desired objective of a specific application.Like in a PV system,to obtain the inherent capability of a DC–DC converter for operating at the maximum power point(MPP)and thereby electronically extracting the maximum power from the source.Hence,a detailed review of topological advancements on the low to medium-voltage and medium-to-high-power DC–DC converters has been carried out.Moreover,a thorough investigation has been carried out on profuse closed-loop strategies and compared with each other for obtaining the optimum or maximum output performance and thereby obtaining the utmost source utilization.The modern control techniques though have relatively more calculation time but,they tend to reduce the steady-state error that leads to the stabilization of the converter.Lastly,certain applications of the DC–DC converters have been explained to get an overall idea of the usefulness of such power converters.
基金Supported by the Natural Science Foundation for Distinguished Young Scholars of Guangdong Province(2022B1515020002).
文摘In today’s fast-paced,information-driven world,data centers can offer high-speed,intricate capabilities on a larger scale owing to the ever-growing demand for networks and information systems.Because data centers process and transmit information,stability and reliability are important.Data center power supply architectures rely heavily on isolated bidirectional DC-DC converters to ensure safety and stability.For the smooth operation of a data center,the power supply must be reliable and uninterrupted.In this study,we summarize the basic principle,topology,switch conversion strategy,and control technology of the existing isolated bidirectional DC-DC converters.Subsequently,existing research results and problems with isolated bidirectional DC-DC converters are reviewed.Finally,future trends in the development of isolated bidirectional DC-DC converters for data centers are presented,which offer valuable insights for solving engineering obstacles and future research directions in the field.
文摘This paper presents an isolated DC/AC/DC converter using a middle frequency transformer coupling two modular multilevel converters(MMC),suitable for interconnecting DC transmission lines of different voltage levels in high voltage direct current(HVDC)system.The basic operational principle of the isolated module multilevel DC/DC converter(IMMDCC)is analyzed.The dynamic model of IMMDCC is studied in detail and the transient relationship between DC side and AC side of IMMDCC is revealed,which is physically straightforward for understanding the power transfer in IMMDCC.The control strategy in D-Q coordinate system is put forward,and the fault characteristic and corresponding protection method is analyzed.Finally,computer simulation using Matlab/Simulink is performed to verify the dynamic model and the proposed control strategy.The simulation results show good performances and the quick response ability of the proposed control strategy.
基金supported by research grant of Guangxi Key Laboratory Traditional Chinese Medicine Quality Standards (No. GXGZZK201501)the Open Research Fund Program of Guangxi Key Laboratory of Marine Biotechnology (No. GLMBT-201407)+1 种基金partly supported by Shanghai Fengxian District Science and Technology Project (Nos. 20141001 and 20151205)Shanghai No. 6 People’s Medical Group Project and research project of Shanghai municipal health and Family Planning Commission (No. 201540027)
文摘Three angiotensin I converting enzyme(ACE) inhibition peptides were isolated from sandworm Sipunculus nudus protein hydrolysate prepared using protamex. Consecutive purification methods, including size exclusion chromatography and reverse-phase high performance liquid chromatography(RP-HPLC), were used to isolate the ACE inhibition peptides. The amino acid sequences of the peptides were identified as Ile-Asn-Asp, Val-Glu-Pro-Gly and Leu-Ala-Asp-Glu-Phe. The IC_(50) values of the purified peptides for ACE inhibition activity were 34.72 μmol L^(-1), 20.55 μmol L^(-1) and 22.77 μmol L^(-1), respectively. These results suggested that S. nudus proteins contain specific peptides that can be released by enzymatic hydrolysis. This study may provide an experimental basis for further systematic research, rational development and clinical utilization of sandworm resources.