当前,高频换流器实时仿真在仿真精度和仿真灵活性上难以兼顾。为此采用了基于FPGA+PC的实时多速率协同仿真方法,全面展示了多速率协同仿真系统的仿真原理,以及硬件设计与实现。在30 k Hz/50 k Hz三相两电平逆变算例仿真的研究中,呈现了...当前,高频换流器实时仿真在仿真精度和仿真灵活性上难以兼顾。为此采用了基于FPGA+PC的实时多速率协同仿真方法,全面展示了多速率协同仿真系统的仿真原理,以及硬件设计与实现。在30 k Hz/50 k Hz三相两电平逆变算例仿真的研究中,呈现了换流器建模、算例模型分割和电路求解器实现。以离线精确模型为基准,将多速率协同仿真平台与PC实时仿真平台的实验结果从仿真波形、仿真误差及实时性方面进行比较。结果表明,在开关频率50 k Hz以下多速率仿真的速率转换误差收敛,电磁暂态仿真欧式范数误差达到1%左右,仿真平台仿真步长达到500 ns。该方法提高了高频换流器实时仿真精度、减小了仿真步长,为高性能协同仿真平台的设计提供了参考。展开更多
Graphene is considered as a promising material to construct field-effect transistors (FETs) for high frequency electronic applications due to its unique structure and properties,mainly including extremely high carrier...Graphene is considered as a promising material to construct field-effect transistors (FETs) for high frequency electronic applications due to its unique structure and properties,mainly including extremely high carrier mobility and saturation velocity,the ultimate thinnest body and stability.Through continuously scaling down the gate length and optimizing the structure,the cut-off frequency of graphene FET (GFET) was rapidly increased and up to about 300 GHz,and further improvements are also expected.Because of the lack of an intrinsic band gap,the GFETs present typical ambipolar transfer characteristic without off state,which means GFETs are suitable for analog electronics rather than digital applications.Taking advantage of the ambipolar characteristic,GFET is demonstrated as an excellent building block for ambipolar electronic circuits,and has been used in applications such as highperformance frequency doublers,radio frequency mixers,digital modulators,and phase detectors.展开更多
Modeling and investigation of HF electromagnetic heating in induction devices with unclosed magnetic circuit has allowed to optimize heating speed in local zones of formation of soldering connections and to improve th...Modeling and investigation of HF electromagnetic heating in induction devices with unclosed magnetic circuit has allowed to optimize heating speed in local zones of formation of soldering connections and to improve their quality due to joint action of superficial effects and electromagnetic forces.For all magnetic materials is nonlinear decrease in heating power depending on frequency of HF.Installed the optimal parameters of HF heating for soldering electronics modules by inductor with open-ended magnetic conductor.展开更多
针对变流器不同位置杂散电感准确获取困难的问题,提出一种基于LC高频振荡原理的杂散电感多参数提取方法,充分利用变流器自身结构,通过3个现场实验主动构建不同的谐振电路,并根据它们的振荡频率计算变流器不同位置的杂散电感。首先阐述...针对变流器不同位置杂散电感准确获取困难的问题,提出一种基于LC高频振荡原理的杂散电感多参数提取方法,充分利用变流器自身结构,通过3个现场实验主动构建不同的谐振电路,并根据它们的振荡频率计算变流器不同位置的杂散电感。首先阐述了高频振荡法的基本原理,建立了不同谐振实验的等值电路模型。然后,以1700 V/450 A IGBT变流器系统为例,通过仿真与实验进行了可行性与有效性验证。最后,通过实验与传统双脉冲法进行了对比分析。研究表明:所提出的方法可有效提取变流器内不同位置的杂散电感参数,与双脉冲法提取开关杂散电感结果基本一致,精度可达纳亨级。展开更多
文摘当前,高频换流器实时仿真在仿真精度和仿真灵活性上难以兼顾。为此采用了基于FPGA+PC的实时多速率协同仿真方法,全面展示了多速率协同仿真系统的仿真原理,以及硬件设计与实现。在30 k Hz/50 k Hz三相两电平逆变算例仿真的研究中,呈现了换流器建模、算例模型分割和电路求解器实现。以离线精确模型为基准,将多速率协同仿真平台与PC实时仿真平台的实验结果从仿真波形、仿真误差及实时性方面进行比较。结果表明,在开关频率50 k Hz以下多速率仿真的速率转换误差收敛,电磁暂态仿真欧式范数误差达到1%左右,仿真平台仿真步长达到500 ns。该方法提高了高频换流器实时仿真精度、减小了仿真步长,为高性能协同仿真平台的设计提供了参考。
基金supported by the Ministry of Science and Technology of China(2011CB933001and2011CB933002)the National Natural Science Foundation of China(61071013)
文摘Graphene is considered as a promising material to construct field-effect transistors (FETs) for high frequency electronic applications due to its unique structure and properties,mainly including extremely high carrier mobility and saturation velocity,the ultimate thinnest body and stability.Through continuously scaling down the gate length and optimizing the structure,the cut-off frequency of graphene FET (GFET) was rapidly increased and up to about 300 GHz,and further improvements are also expected.Because of the lack of an intrinsic band gap,the GFETs present typical ambipolar transfer characteristic without off state,which means GFETs are suitable for analog electronics rather than digital applications.Taking advantage of the ambipolar characteristic,GFET is demonstrated as an excellent building block for ambipolar electronic circuits,and has been used in applications such as highperformance frequency doublers,radio frequency mixers,digital modulators,and phase detectors.
文摘Modeling and investigation of HF electromagnetic heating in induction devices with unclosed magnetic circuit has allowed to optimize heating speed in local zones of formation of soldering connections and to improve their quality due to joint action of superficial effects and electromagnetic forces.For all magnetic materials is nonlinear decrease in heating power depending on frequency of HF.Installed the optimal parameters of HF heating for soldering electronics modules by inductor with open-ended magnetic conductor.
文摘针对变流器不同位置杂散电感准确获取困难的问题,提出一种基于LC高频振荡原理的杂散电感多参数提取方法,充分利用变流器自身结构,通过3个现场实验主动构建不同的谐振电路,并根据它们的振荡频率计算变流器不同位置的杂散电感。首先阐述了高频振荡法的基本原理,建立了不同谐振实验的等值电路模型。然后,以1700 V/450 A IGBT变流器系统为例,通过仿真与实验进行了可行性与有效性验证。最后,通过实验与传统双脉冲法进行了对比分析。研究表明:所提出的方法可有效提取变流器内不同位置的杂散电感参数,与双脉冲法提取开关杂散电感结果基本一致,精度可达纳亨级。
