This paper compares the flame acceleration in single-trial dual-detonation tubes triggered by a spark plug and non-thermal plasma igniter. The low-temperature plasma was generated by an in-house novel AC-driven dielec...This paper compares the flame acceleration in single-trial dual-detonation tubes triggered by a spark plug and non-thermal plasma igniter. The low-temperature plasma was generated by an in-house novel AC-driven dielectric barrier discharge igniter, which reduces the power supply requirements and was applied in the quiescent ignition of a single-trial detonation tube. Three different types of detonation mixtures were tested with flame propagation tracked by ion probes and pressure waves recorded by high-frequency pressure transducers. The flame propagation speeds were calculated and compared based on signals from the ion probes. The detonation combustion succeeded in the dual tubes, but the deflagration-to-detonation transition could be significantly accelerated by the plasma for all mixtures, as it was shortened by more than 50% compared to that of the spark plug. The present study provides a suitable technological approach for igniters of PDEs.展开更多
An atmospheric-pressure carbon dioxide(CO_2) plasma jet(CPJ) produced by alternating current driven non-thermal arc plasma torch is presented.The discharge features of CPJ and their non-linear behavior are analyzed ba...An atmospheric-pressure carbon dioxide(CO_2) plasma jet(CPJ) produced by alternating current driven non-thermal arc plasma torch is presented.The discharge features of CPJ and their non-linear behavior are analyzed based on the temporal evolution of voltage and current.With the increase of gas flowrate,the quantities of the current and voltage spikes increase in an operation cycle of power supply.The spatial gas temperature distribution is obtained by the gray value method,which basically agrees well with that of determined by the diatomic molecule of OH fitting method in experimental errors.展开更多
为解决由于功率失配引起的分布式发电系统频率偏差问题,该文针对带电池储能系统(battery energy storagesystem,BESS)的多智能体交流微电网,提出了一种基于低带宽通信网络的分布式有限时间控制算法。该控制算法以Lyapunov方法和齐次逼...为解决由于功率失配引起的分布式发电系统频率偏差问题,该文针对带电池储能系统(battery energy storagesystem,BESS)的多智能体交流微电网,提出了一种基于低带宽通信网络的分布式有限时间控制算法。该控制算法以Lyapunov方法和齐次逼近理论为基础,可确保系统节点不依赖初始条件,在一定时间内加速收敛。另外,为减轻通信负担,设计了一种能够避免芝诺(Zeno)行为的事件驱动通信机制,并导出了该行为触发边界的充分条件。通过模拟多个孤岛交流微电网案例进行仿真分析。研究结果表明,与传统控制器相比,所提出的控制算法在保证收敛时间不随初始条件变化的前提下,可以协调BESS以消除其与标准频率的偏差,同时解决荷电状态(state ofcharge,SoC)平衡问题,提高了同步速度,降低通信负担,确保了整个系统的稳定性和可靠性。展开更多
针对从周围环境中收集能量的微型发电机输出功率和电压非常小,无法直接应用的问题。文中设计了一种超低输入电压、低功耗且高效的接口电路。该接口电路包含两级,第一级是无源级和仅由一个有源二极管组成的第二级。为降低有源二极管的功...针对从周围环境中收集能量的微型发电机输出功率和电压非常小,无法直接应用的问题。文中设计了一种超低输入电压、低功耗且高效的接口电路。该接口电路包含两级,第一级是无源级和仅由一个有源二极管组成的第二级。为降低有源二极管的功耗,采用一个工作在亚阈值区的衬底输入比较器用来驱动MOS开关。设计采用TSMC 0.18μm标准CMOS工艺,使用Cadence Spectre在室温的条件下进行仿真。结果表明,在输入电压为500 m V(100 Hz),负载电阻为50 kΩ时整流器的电压转换率为97.7%,能量转换率为91.3%。整流器能够在输入电压振幅为320 m V以上实现高效整流。展开更多
This report shows how starting from classic electric circuits embodying commonly electric components we have reached semi-complicated circuits embodying the same components that analyzing the signal characteristics re...This report shows how starting from classic electric circuits embodying commonly electric components we have reached semi-complicated circuits embodying the same components that analyzing the signal characteristics requires a Computer Algebra System. Our approach distinguishes itself from the electrical engineers’ (EE) approach that relies on utilizing commercially available software. Our approach step-by-step shows how Kirchhoff’s rules are applied conducive to the needed circuit information. It is shown for the case at hand the characteristic information is a set of coupled differential equations and that with the help of Mathematica numeric solutions are sought. Our report paves the research road for unlimited creative similar circuits with any degree of complications. Occasionally, by tweaking the circuits we have addressed the “what if” scenarios widening the scope of the investigation. Justification of the accuracy of our analysis for the generalized circuits is cross-checked by arranging the components symmetrizing the circuit leading to an intuitively predictable reasonable result. Mathematica codes are embedded assisting the interested reader in producing and extending our results.展开更多
文章基于可编程SNS型约瑟夫森结阵,研究了一种交流量子电压驱动方法。该方法根据结阵的I-V特性,通过控制各段结阵的偏置状态及组合方式,实现交流量子电压的合成。采用电压源驱动方式,将节点电流分析法应用在偏置电路参数计算中,设计了...文章基于可编程SNS型约瑟夫森结阵,研究了一种交流量子电压驱动方法。该方法根据结阵的I-V特性,通过控制各段结阵的偏置状态及组合方式,实现交流量子电压的合成。采用电压源驱动方式,将节点电流分析法应用在偏置电路参数计算中,设计了偏置模块,搭建了交流约瑟夫森量子电压驱动系统。实验结果表明,该系统偏置电流的建立时间为1.27μs,稳定性优于6 n A/min,输出电流分辨率可达0.01 m A,可以合成频率为50 Hz、每周期40个采样点、有效值为1 V的交流约瑟夫森量子电压信号。展开更多
基金support of the National Natural Science Foundation of China(Nos.51176001 and 51676111)the Tsinghua University Initiative Scientific Research Program(No.2014Z05091)the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions
文摘This paper compares the flame acceleration in single-trial dual-detonation tubes triggered by a spark plug and non-thermal plasma igniter. The low-temperature plasma was generated by an in-house novel AC-driven dielectric barrier discharge igniter, which reduces the power supply requirements and was applied in the quiescent ignition of a single-trial detonation tube. Three different types of detonation mixtures were tested with flame propagation tracked by ion probes and pressure waves recorded by high-frequency pressure transducers. The flame propagation speeds were calculated and compared based on signals from the ion probes. The detonation combustion succeeded in the dual tubes, but the deflagration-to-detonation transition could be significantly accelerated by the plasma for all mixtures, as it was shortened by more than 50% compared to that of the spark plug. The present study provides a suitable technological approach for igniters of PDEs.
文摘An atmospheric-pressure carbon dioxide(CO_2) plasma jet(CPJ) produced by alternating current driven non-thermal arc plasma torch is presented.The discharge features of CPJ and their non-linear behavior are analyzed based on the temporal evolution of voltage and current.With the increase of gas flowrate,the quantities of the current and voltage spikes increase in an operation cycle of power supply.The spatial gas temperature distribution is obtained by the gray value method,which basically agrees well with that of determined by the diatomic molecule of OH fitting method in experimental errors.
文摘为解决由于功率失配引起的分布式发电系统频率偏差问题,该文针对带电池储能系统(battery energy storagesystem,BESS)的多智能体交流微电网,提出了一种基于低带宽通信网络的分布式有限时间控制算法。该控制算法以Lyapunov方法和齐次逼近理论为基础,可确保系统节点不依赖初始条件,在一定时间内加速收敛。另外,为减轻通信负担,设计了一种能够避免芝诺(Zeno)行为的事件驱动通信机制,并导出了该行为触发边界的充分条件。通过模拟多个孤岛交流微电网案例进行仿真分析。研究结果表明,与传统控制器相比,所提出的控制算法在保证收敛时间不随初始条件变化的前提下,可以协调BESS以消除其与标准频率的偏差,同时解决荷电状态(state ofcharge,SoC)平衡问题,提高了同步速度,降低通信负担,确保了整个系统的稳定性和可靠性。
文摘针对从周围环境中收集能量的微型发电机输出功率和电压非常小,无法直接应用的问题。文中设计了一种超低输入电压、低功耗且高效的接口电路。该接口电路包含两级,第一级是无源级和仅由一个有源二极管组成的第二级。为降低有源二极管的功耗,采用一个工作在亚阈值区的衬底输入比较器用来驱动MOS开关。设计采用TSMC 0.18μm标准CMOS工艺,使用Cadence Spectre在室温的条件下进行仿真。结果表明,在输入电压为500 m V(100 Hz),负载电阻为50 kΩ时整流器的电压转换率为97.7%,能量转换率为91.3%。整流器能够在输入电压振幅为320 m V以上实现高效整流。
文摘This report shows how starting from classic electric circuits embodying commonly electric components we have reached semi-complicated circuits embodying the same components that analyzing the signal characteristics requires a Computer Algebra System. Our approach distinguishes itself from the electrical engineers’ (EE) approach that relies on utilizing commercially available software. Our approach step-by-step shows how Kirchhoff’s rules are applied conducive to the needed circuit information. It is shown for the case at hand the characteristic information is a set of coupled differential equations and that with the help of Mathematica numeric solutions are sought. Our report paves the research road for unlimited creative similar circuits with any degree of complications. Occasionally, by tweaking the circuits we have addressed the “what if” scenarios widening the scope of the investigation. Justification of the accuracy of our analysis for the generalized circuits is cross-checked by arranging the components symmetrizing the circuit leading to an intuitively predictable reasonable result. Mathematica codes are embedded assisting the interested reader in producing and extending our results.
文摘文章基于可编程SNS型约瑟夫森结阵,研究了一种交流量子电压驱动方法。该方法根据结阵的I-V特性,通过控制各段结阵的偏置状态及组合方式,实现交流量子电压的合成。采用电压源驱动方式,将节点电流分析法应用在偏置电路参数计算中,设计了偏置模块,搭建了交流约瑟夫森量子电压驱动系统。实验结果表明,该系统偏置电流的建立时间为1.27μs,稳定性优于6 n A/min,输出电流分辨率可达0.01 m A,可以合成频率为50 Hz、每周期40个采样点、有效值为1 V的交流约瑟夫森量子电压信号。
