High-Speed,Robust CMOS Dynamic Circuit Design

A novel circuit with a narrow pulse driving structure is proposed for enhancing the noise immunity and improving the performance of wide fan-in dynamic circuits. Also,an analytical mode that agrees well with simulations is presented for transistor sizing. Simulation results show that an improvement of up to 12% over the conventional technique at 1GHz is obtained with this circuit,which can run 1.6 times faster than the existing technique with the same noise immunity.

AN ANALYSIS METHOD FOR HIGH-SPEED CIRCUIT SYSTEMS

A new method for analyzing high-speed circuit systems is presented. The method adds transmission line end currents to the circuit variables of the classical modified nodal approach. Then the matrix equation describing high-speed circuit system can be formulated directly and analyzed conveniently for its normative form. A time-domain analysis method for transmission lines is also introduced. The two methods are combined together to efficiently analyze high-speed circuit systems having general transmission lines. Numerical experiment is presented and the results are compared with that calculated by Hspice.

Electromagnetic Analysis and Optimization of High-speed Maglev Linear Synchronous Motor Based on Field-circuit Coupling

High speed maglev train has become a new non-contact transportation mode mainly studied in recent years because of its non-sticking and high speed characteristics.Firstly,the finite element model of the long stator linear synchronous motor(LSM)is established based on the structure of the test prototype.After calculation,it is compared with the experimental data and verified.On this basis,a field-circuit coupling model based on inverter circuit is established,and the influence of carrier wave ratio change on the output characteristics of LSM is calculated and analyzed.Finally,the filter circuit is introduced into the field-circuit coupling model,and the influence of the filter circuit on the output characteristics of the LSM is compared and analyzed.

Sensitivity analysis of distributed parameter elements in high-speed circuit networks

This paper presents an analysis method, based on MacCormack＇s technique, for the evaluation of the time domain sensitivity of distributed parameter elements in high-speed circuit networks. Sensitivities can be calculated from electrical and physical parameters of the distributed parameter elements. The proposed method is a direct numerical method of time-space discretization and does not require complicated mathematical deductive process. Therefore, it is very convenient to program this method. It can be applied to sensitivity analysis of general transmission lines in linear or nonlinear circuit networks. The proposed method is second-order-accurate. Numerical experiment is presented to demonstrate its accuracy and efficiency.

Analysis of Temperature Rise in High-Speed Permanent Magnet Synchronous Traction Motors by Coupling the Equivalent Thermal Circuit Method and Computational Fluid Dynamics

To solve the problem of temperature rise caused by the high power density of high-speed permanent magnet synchronous traction motors,the temperature rise of various components in the motor is analyzed by coupling the equivalent thermal circuit method and computational fluid dynamics.Also,a cooling strategy is proposed to solve the problem of temperature rise,which is expected to prolong the service life of these devices.First,the theoretical bases of the approaches used to study heat transfer and fluid mechanics are discussed,then the fluid flow for the considered motor is analyzed,and the equivalent thermal circuit method is introduced for the calculation of the temperature rise.Finally,the stator,rotor loss,motor temperature rise,and the proposed cooling method are also explored through experiments.According to the results,the stator temperature at 50,000 r/min and 60,000 r/min at no-load operation is 68℃ and 76℃,respectively.By monitoring the temperature of the air outlets inside and outside the motor at different speeds,it is also found that the motor reaches a stable temperature rise after 65 min of operation.Coupling of the thermal circuit method and computational fluid dynamics is a strategy that can provide the average temperature rise of each component and can also comprehensively calculate the temperature of each local point.We conclude that a hybrid cooling strategy based on axial air cooling of the inner air duct of the motor and water cooling of the stator can meet the design requirements for the ventilation and cooling of this type of motors.

Minimizing crosstalk for high-speed and high-density bus systems using the sample-decision method

This paper presents a method based on a sample-decision(SD) circuit to suppress crosstalk and noise for a high-speed and high-density bus system.A method to count the number of times of SD for different length of transmission lines is presented and a bit error rates(BERs) formula is given by the SD circuit.It is shown that for long transmission line systems,multiple SD circuits can improve the BERs significantly.Circuits simulation for single SD method is also done,it is found that when the amplitude peak values of the superposed crosstalk and noise are less than half of the corresponding signal ones,they will be eliminated completely for the cases investigated.

Power supply arm protection scheme of high-speed railway based on wide-area current differential

When fault occurs on cross-coupling autotransformer(AT)power supply traction network,the up-line and down-line feeder circuit breakers in the traction substation trip at the same time without selectivity,which leads to an extended power failure.Based on equivalent circuit and Kirchhoff’s current law,the feeder current characteristic in the substation,AT station and sectioning post when T-R fault,F-R fault,and T-F fault occur are analyzed and their expressions are obtained.When the traction power supply system is equipped with wide-area protection measurement and control system,the feeder protection device in each station collects the feeder currents in other two stations through the wide-area protection channel and a wide-area current differential protection scheme based on the feeder current characteristic is proposed.When a short-circuit fault occurs in the power supply arm,all the feeder protection devices in each station receive the feeder currents with time stamp in other two stations.After data synchronous processing and logic judgment,the fault line of the power supply arm can be identified and isolated quickly.The simulation result based on MATLAB/Simulink shows that the power supply arm protection scheme based on wide-area current differential has good fault discrimination ability under different fault positions,transition resistances,and fault types.The verification of measured data shows that the novel protection scheme will not be affected by the special working conditions of the electrical multiple unit(EMU),and reliability,selectivity,and rapidity of relay protection are all improved.

New Design Methodologies for High Speed Low-Voltage 1-Bit CMOS Full Adder Circuits

New methodologies for l-Bit XOR-XNOR full- adder circuits are proposed to improve the speed and power as these circuits are basic building blocks for ALU circuit implementation. This paper presents comparative study of high-speed, low-power and low voltage full adder circuits. Simulation results illustrate the superiority of the proposed adder circuit against the conventional complementary metal-oxide-semiconductor （CMOS）, complementary pass-transistor logic （CPL）, TG, and Hybrid adder circuits in terms of delay, power and power delay product （PDP）. Simulation results reveal that the proposed circuit exhibits lower PDP and is more power efficient and faster when compared with the best available 1-bit full adder circuits. The design is implemented on UMC 0.18 μm process models in Cadence Virtuoso Schematic Composer at 1.8 V single ended supply voltage and simulations are carried out on Spectre S.

Design of a Low-Power CMOS LVDS I/O Interface Circuit

The paper presents the design and implementation of LVDS （low-voltage differential signaling） receiver circuit, fully compatible with LVDS standard. The proposed circuit is composed of the telescopic amplifier and the comparator with internal hysteresis. The receiver supports 3.5 Gbps data rate with 7.4 mA current at 1.8 V supply according to post-layout circuit simulations. The circuit has the power consumption of 13.1 MW. Comparing with the conventional circuit, the circuit is achieved to reduce the power consumption by 19.1% and the data rate by 14.3 %. The validity and effectiveness of the proposed circuit are verified through the circuit simulation with Samsung 0.18 μm CMOS （complementary metal-oxide-semiconductor） standard technology under the 1.8 V supply voltage.

中波发射台雷电预警系统应用设计

中波发射台应用的发射天线通常较高,容易遭遇雷电侵袭。雷电侵袭时,目前只能采取被动的防护措施,如果防护不及时,会损坏发射设备甚至危及工作人员的人身安全。因此,如何加强雷电防护是中波发射台迫切需要解决的问题。基于此,详细介绍了雷电预警系统的电路组成、工作原理、调试方法、使用方法及注意事项。

Realization of Rapid Debugging for Detection Circuit of Optical Fiber Gas Sensor： Using an Analog Signal Source

An optical fiber gas sensor mainly consists of two parts： optical part and detection circuit. In the debugging for the detection circuit, the optical part usually serves as a signal source. However, in the debugging condition, the optical part can be easily influenced by many factors, such as the fluctuation of ambient temperature or driving current resulting in instability of the wavelength and intensity for the laser; for dual-beam sensor, the different bends and stresses of^the optical fiber will lead to the fluctuation of the intensity and phase; the intensity noise from the collimator, coupler, and other optical devices in the system will also result in the impurity of the optical part based signal source. In order to dramatically improve the debugging efficiency of the detection circuit and shorten the period of research and development, this paper describes an analog signal source, consisting of a single chip microcomputer （SCM）, an amplifier circuit, and a voltage-to-current conversion circuit. It can be used to realize the rapid debugging detection circuit of the optical fiber gas sensor instead of optical part based signal source. This analog signal source performs well with many other advantages, such as the simple operation, small size, and light weight.

电气调试中电子电路的干扰问题研究

在电气调试过程中,实时监测和精确控制电子电路的干扰问题至关重要。相关单位应严格把控调试细节及方案,通过合理布局电路、引入屏蔽技术、优化设计、控制电源噪声、选择高抗干扰性能的电子元器件、加强电气调试人员的技能培训和指导,以及引入人工智能分析等措施,提高电气调试电子电路抗干扰管控水平。简要分析了电气调试中电子电路的干扰问题,并提出了对应的解决方案。

电厂继电保护二次回路的调试技术研究

继电保护二次回路的调试是实现电厂安全生产的关键,具有较好的社会价值与经济价值。文章分析了电厂继电保护二次回路调试的相关内容,在总结相关学者研究现状的基础上,对继电保护二次回路调试要点展开研究。采用案例分析法,详细剖析调试过程中发现的问题及其解决措施,并对继电保护二次回路调试技术的发展进行展望,为提升电厂继电保护水平提供有力的支撑。

应用微型模拟断路器进行自动化调试方法研究

基建变电站工程一般把测控装置与实际断路器、刀闸联系起来进行调试,自动化调试必须等待断路器及刀闸设备安装完毕、二次回路调试完成后才可进行,存在局限性,同时需要断路器、刀闸实际动作的次数多、频率高。若自动化调试验收期间出现设备故障或二次回路有误、断路器刀闸等设备有交叉作业等问题时,则会使施工进度受阻。针对现有做法无法避免交叉作业导致设备自动化调试工作进度受到影响的问题,技术人员受备自投调试中投入使用模拟断路器代替一次断路器进行调试的启发,研究出使用模拟断路器代替实际断路器及刀闸进行设备自动化调试的方法,以达到设备自动化调试验收工作不受断路器、刀闸安装施工和二次回路调试影响的效果。本文就上述内容展开研究。

可在线编程的多功能单片机实验板

实验板以SST89E564RD单片机为核心,兼顾学生单片机实验和毕业设计等不同用途,集成了I2C、SPI等多种总线协议,具有串口在线调试、编程和脱机运行等功能,应用Keil C51 uV2集成开发环境．它具有模块化硬件结构和简单的人机交互功能,在测量、控制、实时时钟和数据存储等用途中,可选取相应模块组成实际应用系统．详细阐述了系统组成、硬件系统设计、监控程序和实验程序的开发．

CINRAD/SA雷达回扫充电控制电路调试技巧及故障处理

从济南新一代天气雷达CINRAD/SA的日常测试与调试工作出发,着重介绍了发射机回扫充电控制系统3A10组件的调试方法与注意事项,同时简述了实际工作中出现的常见故障、成因及其排除方法,旨在使技术保障人员掌握该雷达测试与调试的方法,能在最短的时间内排除设备故障,保障雷达处于良好的运转状态。

基于PIC16F876单片机的智能低压电动机综合保护器的研究

为解决市场上现有各种电动机保护器功能与成本之间的矛盾,研制了一款高性价比的以Microchip公司的PIC16F876单片机为核心的智能低压电动机综合保护器。重点介绍了热过载保护的反时限特性和启动保护与运行保护的区别。提出了一种特定算法用于程序中的计算,有效地解决了定点运算精度低和浮点运算计算量大、计算时间长的问题。在装置的结构和软硬件设计中,采用了多种抗干扰措施,以提高装置的可靠性与抗干扰能力。动态模拟试验和现场运行结果表明,此保护器能对低压电动机的各种故障做出准确判断且具有良好的可靠性、重复性,其动作值、动作时间的精度能达到一般工业现场要求。

电传动自卸车电气传动系统电制动器设计

电传动自卸车作为重要的大载重量运输设备,当其在较高的车速下制动时,传统单独的机械制动已不能满足需要,而电制动作为重要的制动形式在此种工况下发挥重要作用,是车辆安全性运行的重要保证。根据电制动器的结构特点和功能特征,以某自卸车1700V/200A电制动器设计与实现为依托,对电制动器进行电路和软件设计及调试。在电制动器的研究中,按照电动轮车辆电气传动系统的功率级别,选择高可靠性的大功率电力电子器件,设计并实现了一款能够满足研究车辆功率需求的1200V200A制动器系统,该系统也基于32位DSP处理器和CAN总线。搭建电传动系统试验台,通过电制动器实验证明可以实现设计的全部功能,并且其功率已经可以满足研究车辆的电气传动系统中电制动器需要,为实车试验及同类产品设计提供参考。

一种带有流水线追踪器的JTAG ICE调试电路设计

针对复旦大学自主开发的32位RISCCPU,设计了相应JTAG调试电路(In-CircuitEmulator)。为解决此RISCCPU中5级流水线导致的断点误停的问题,提出了一种新颖的带有分支预测功能的电路结构─“流水线追踪器”。此JTAG调试电路与IEEE1149.1标准兼容,具有设置断点、单步、查看或修改CPU寄存器/内存空间、在线FLASH编程等多种功能。

阻塞斩波三相交交变频电源的FPGA控制实现

变频技术是重要的节能技术,所以针对低频或转速不恒定的节能设备,提出了基于FPGA数字控制的三相交交直接变频电源技术。用VHDL语言对主控芯片FPGA编写程序,其输出的高频SPWM信号经驱动电路后作为电源和负载间开关MOSFET的控制信号。MOSFET周期性地部分阻塞电源不能达到负载来改变输出电压的频率,同时在放行的时区斩波来改变输出电压的幅值。基于Matlab仿真平台,对系统进行了建模和仿真,仿真结果验证了该技术的正确性。最后给出了频率为7.14 Hz和2.63 Hz的实验波形,实验结果证明了该技术的可行性。