实现电功率双路测量的方法及电路的非线性度分析

提出了一种实现有功功率和真无功功率双栖测量的方法,对测量方法的原理进行了数学证明,并根据数学公式提出了实现其测量方法的各部分电路原理及其实现方法。对影响测量准确度的关键电路,即功率测量电路的测量非线性度进行了动态分析,提出了电路测量线性度的计算公式,并就影响测量误差线性度的电路关键参数进行了计算机仿真研究。     

A genetic circuit amplifier: design and simulation

A genetic circuit amplifier is designed using an electronic inverting amplifier as a starting point. Two simulation methods are used to analyze circuit performance in terms of the impulse and sinusoidal responses of electrical engineering. The first method is an exact stochastic simulation based on a kinetic model of the circuit. The second method incorporates statistical thermodynamic analysis. The simulations are used to analyze amplifier performance in response to classical systems analysis stimuli: impulses and sine waves. Degradation reactions, analogous to leakage off circuit capacitors, are found to have considerable impact on circuit response. For the nonlinear gain element used in our exemplary circuit, the selection of bias level based on controlling protein degradation rate plays an important role in determining circuit behavior. A parameter without electronic analog, the circuit plasmid copy number, is crucial to circuit operation. These simulations suggest that the copy number must be less than 50 for desired circuit operation.     

基于遗传算法的振荡器谐振回路的参数选择

针对振荡器谐振回路参数选择较多依赖于经验的问题,提出从振荡器的等效电路出发,得到描述振荡器的非线性微分方程,通过引入随机项来描述振荡器的内部电噪声,由此建立用于分析振荡器行为的非线性随机微分方程;并运用遗传算法对振荡器谐振回路进行参数优选,得到适应度以相位噪声最小为优化准则的参数,用该参数进行数值研究,结果表明了该方法的有效性,为振荡器的分析和谐振回路参数的优选提供了一种新方法.     

FMEA在某选频电路故障仿真中的应用

针对元器件单故障模式数量太多,电路故障仿真的工作量庞大,工程上难以实现这一问题,提出了采用FMEA分析技术在电路中进行故障分析的方法,获取发生故障概率较高、对系统危害程度较大的故障模式,并可相应得到对该故障模式影响较大的元件,这样可以进行有针对性的仿真,减少仿真设置故障的次数和仿真工作量.将其用于某选频电路故障仿真中,数值结果表明该方法的有效性和正确性.     

基于电路压缩的单开路故障快速分析算法

基于多网格和等效电路这两种电路压缩方法,提出了一种电源线/地线(P/G)网络单故障高效分析算法,以有效地提高P/G网单开路电阻故障的测试效率.该算法包括3个算法步骤:先采用多网格方法和等效电路方法对电路进行大幅度地压缩,此过程具有快速与高精度的优点,再采用连续过松弛(SOR)求解算法求解剩余电路的电压分布,最后根据已知电压节点快速而精确地返算出被压缩节点的电压.实验数据表明:该算法具有精度高、算法复杂性低、应用范围广等优点.与通用的不完全乔勒斯基分解共轭梯度(ICCG)求解算法相比,该算法在保持较高精度(误差小于0.0276%)的前提下,速度可以提高106倍,同时还可以求解ICCG算法无法处理的测例.     

Modified nodal analysis: an essential addition to electricalcircuit theory and analysis

The known limitations of classical mesh and nodal methods of analysing linear electrical circuits are described before considering an established modification of the nodal approach. The method, known as 'modified nodal analysis', has none of the limitations of the basic nodal technique and is well suited both to symbolic and numeric analysis of complex circuits using modern matrix-based software. The simplicity of incorporating into the matrix equations all types of passive and active circuit elements is demonstrated and examples are used to illustrate further the efficacy of the method. It is emphasised that the absence of this circuit analysis technique from many academic engineering courses is totally at variance with its widespread application in modern circuit simulation packages     

照明用大功率无桥LED驱动电路输入电流谐波分析

对作者介绍的照明用大功率无桥LED驱动电路的输入交流工频电流波形在设定电路条件后的频谱和谐波含量进行了分析和计算,其结果是,在电路最低工作频率以下的频率范围内基本不存在谐波成分,电路输入电流的总谐波含量THD随最小输入电流脉冲宽度T₀(min) 增大而上升,随电路的输出直流电压与输入交流电压有效值的比U_o/U_i的增大而下降.并指出在电路的输入端需要一个滤波电路,分析了滤波电路的滤波效果,给出了滤波电路的设计方法.     

机电类比在缓冲包装系统隔振特性分析中的应用

给出了导纳型机电类比的原理、参数对应关系及其绘制方法,应用机电类比方法对缓冲包装系统的隔振特性进行了分析.根据机电类比原理画出了缓冲包装系统的类比电路图,通过电路分析理论对系统的隔振特性进行了定量分析,最后画出了一个多自由度缓冲包装系统的类比电路,从电路原理出发对其进行了定性分析.研究结果表明,导纳型机电类比方法可方便地画出缓冲包装系统的类比电路图,以电路图为基础,可应用成熟的电路分析理论对缓冲包装系统的隔振特性进行分析,此方法能大大简化分析过程.     

一种新型激光陀螺的检测方法

本文通过对新型四频差动激光陀螺输出信号的分析,给出了一种适应新型四频差动激光陀螺输出信号的检测方法。通过APD和高频低噪声前置放大器实现光电接收,通过集中选频放大电路进行滤波和放大,然后采用模拟乘法器实现自乘检波,并根据该方法设计了实际的检测电路。采用直管四频激光器的背向输出来模拟新型四频差动激光陀螺的输出,对电路进行了实际测试。通过测试,验证了检测电路方法的可行性。     

Multi-frequency and multi-layer frequency selective surface analysis using modal decomposition equivalent circuit method

A new modal decomposition equivalent circuit method has been proposed for an analysis of multifrequency and multi-layer frequency selective structure (FSS). The present paper is an extension of the previously published work where it has been shown that the method is valid for `thin? and `thick? FSS both for angles of incidence up to 60°and for any lattices and potentially allows the synthesis of FSS by the optimisation of circuit parameters. Further investigation has shown the methods validity for the analysis of complex FSS geometries. The method has been successfully applied for the analysis of double-ring slot FSS, `A-sandwich? structures and so on. A very good agreement in comparison with the computational electromagnetic software and rigorous methods such as a periodic method of moments has been obtained.     

An unsymmetrical mode of ferroresonance

Earlier studies of ferroresonance note the existence of unsymmetrical modes of operation of series circuits with square-loop reactors. Here the observation of stable second harmonics in a series ferroresonant circuit with a reactor having very nonsquare-loop core material is noted; these harmonics produce unsymmetrical circuit waveforms. Circuit behavior is described, and a qualitative explanation is offered. An approximate solution of the nonlinear circuit equations using the method of reversion of series shows good correlation with the experimental waveforms. From the analysis, the necessary condition for this mode of circuit operation is shown to be the presence of a constant component of flux in the circuit. Potential application of the circuit as a logic element is suggested.     

基于K-means聚类与概率神经网络的模拟电路故障诊断方法

模拟电路已广泛应用于航空电子系统,模拟电路的失效会影响系统的功能,引起系统故障,甚至引发灾难性的安全事故.为快速准确地实现模拟电路的故障诊断,该文引入概率神经网络方法,并针对传统概率神经网络方法中的诊断准确性、诊断效率问题,提出基于K-means与概率神经网络的模拟电路故障诊断方法,定义聚类有效性指标,采用K-mean...     

Magnetic force control based on the inverse magnetostrictive effect

We describe a novel magnetic force control method. The method employs a mechanical stress applied to a magnetostrictive material to control the attractive force between fixed and movable members of a magnetic circuit that includes a permanent magnet. The method has the advantage over electromagnet control that a constant force can be maintained without energy consumption. We discuss the variation of the magnetic force with compression of several magnetostrictive materials. The experimental results agree with theoretical predictions of magnetic force based on analysis of an equivalent magnetic circuit and the piezomagnetic properties of the magnetostrictive materials.     

The variational solution of electric and magnetic circuits

Voltage and current distributions in electric circuits comply with a stationary power condition. An alternative circuit analysis technique can be derived from this property. The unknowns can be varied until the power consumption of the circuit is calculated to be unchanging. At this point the voltages and currents are at their true solution. This variational approach to circuit analysis has been generally overlooked. No doubt this is due to the sufficiency of conventional circuit analysis techniques. However, a closer examination of the variational approach reveals a straightforward analytic procedure with unifying properties and graphically illustrated solutions. These features provide new educational opportunities and insight. As a research tool, the variational approach offers a unified method of solving problems which include fields and devices. The application to nonlinear circuits is also of current interest. An introductory step-by-step guide to the variational procedure for electric and magnetic networks is described in this article     

A new method of determining the equivalent circuit parameters of piezoelectric resonators and analysis of the piezoelectric loading effect

An inductive method of piezoelectric resonance detection is applied to the determination of equivalent circuit parameters of piezoelectric resonators. Using this method one can measure the resonance frequency and mechanical Q-factor of a resonator directly as well as their dependences on the electrical impedance which is connected to the resonator. From the equivalent circuit analysis the changes in resonance frequency and Q-factor due to the piezoelectric loading effects are determined. Measurements on two typical commercial piezoelectric resonators, an AT-cut quartz crystal and a PZT ceramic resonator, are in good agreement with the analysis.     

An analytical investigation on the efficiency of a magnetic frequency tripler with series-connected reactors

A numerical analysis of a magnetic frequency tripler with series-connected reactors and the maximum efficiency under the optimum setting of core dimensions is described. The steady-state values of voltage, current, power, efficiency, and power factor are calculated by using the numerical method where the φ-i characteristics of saturable reactor are approximated by a fifth-order polynomial as a function of core dimensions. The core loss, iron loss, and leakage inductance are included in the equivalent circuit for the numerical analysis. The maximum efficiency is obtained by maximizing the performance index which is derived from numerical results for various values of number of turns, air gap length, and core area as parameters. It is analytically shown that the basic tripler circuit without a LC filter achieves such high efficiency as 90 percent and over. The maximum efficiency of the tripler circuit with the LC filter is about 80 percent.     

发动机测功系统转速检测研究

转速信号是发动机测功系统十分重要的物理量，其检测方法与电路设计直接关系到测功系统的性能和测试控制精度。在详细分析M法、T法和M/T法等测速方法的基础上，本文设计了M／T法测速的硬件电路和自动量程切换的软件实现方法，利用磁电式转速传感器实现了发动机测功系统转速的高精度测量。测速系统实际运行表明，本文设计的非接触式转速测量系统结构简单、抗干扰能力强适用于交、直流全数字化调速系统的数字测速装置的工程设计实践中。     

Designing printed circuit stators for brushless permanent magnet motors

Progress in a number of areas of technology has made printed circuit motors a serious contender for many applications. Modern cost effective neodymium magnets have allowed compact motor designs. Multi-layer circuit board production techniques have made the production of printed circuit coils cheaper and easier. However, in spite of the growing importance of printed circuit brushless motors, there is a lack of analytical tools to assist with their design. Geometrical analysis has been used to allow the plotting of printed circuit tracks to be carried out more systematically. The track plotting procedures have been linked with the finite element method to predict rotational electromotive force (EMF) waveforms. Six prototype motors were built and they were used to experimentally validate the method of predicting EMF waveforms. A general design algorithm is presented based on the suggested track plotting procedure and the EMF prediction technique.     

Performance analysis of single-phase induction motor based on voltage source complex finite-element analysis

In this paper, to make a compromise between accuracy and efficiency in the design of single-phase induction motors, voltage source complex finite-element model, which is combined with the equivalent circuit method to carry out the performance analysis, is presented. The voltage source complex finite-element method is used to determine equivalent circuit parameters by simulating the no-load tests and locked-rotor tests, while the conventional method is adopted to calculate the performances. Good agreement is achieved between the calculated results and test results, which verifies the effectiveness of the presented method.     

管件长度对电磁成形线圈放电电流的影响

为研究电磁成形过程线圈放电电流的变化规律,在放电回路分析的基础上,采用试验分析与代数解析相结合的方法研究了管件长度对线圈放电电流的影响.试验结果表明:随着管件长度的增加,线圈放电电流的幅值和频率均增加.通过解析方法定性分析管件长度对线圈放电电流的影响,其结果与试验结果一致.管件长度不同时,放电回路的等效电感不同,管件长度与等效电感成反比.将管件和成形线圈等效为圆柱线圈可定性分析电磁成形系统的电感和互感.