Passivity–preserving interpolation‐based parameterized model order reduction of PEEC models based on scattered grids

The increasing operating frequencies and decreasing IC feature size call for 3‐D electromagnetic (EM) methods, such as the Partial Element Equivalent Circuit (PEEC) method, as necessary tools for the analysis and design of high‐speed systems. Very large systems of equations are often generated by 3‐D EM methods and model order reduction (MOR) techniques are commonly used to reduce such a high model complexity. A typical design process includes optimization and design space exploration, and hence requires multiple simulations for different design parameter values. Traditional MOR techniques perform model reduction only with respect to frequency and such design activities call for parameterized MOR (PMOR) methods that can reduce large systems of equations with respect to frequency and other design parameters of the circuit, such as geometrical layout or substrate characteristics. We present a novel PMOR technique applicable to the PEEC method that provides parametric reduced order models, stable and passive by construction, over a user defined design space. We treat the construction of parametric reduced order models on scattered design space grids. Pertinent numerical examples validate the proposed approach. Copyright © 2010 John Wiley & Sons, Ltd.     

A novel magneto‐impedance sensor model based on the zeros of Bessel functions

Nowadays, the design of magneto‐impedance (MI) sensors requires the development of lumped circuit models that can be simulated through equivalent impedance circuits relied on Bessel functions. A new impedance model based on Senani's equivalent using the zeros of Bessel functions is developed in this paper. The model allows to describe the impedance as a transfer function that can be easily synthesized by means of current conveyor circuits and passive elements. The mathematical representation was verified under simulation of transfer functions involving different number of poles and zeros. Moreover, the model has been verified using SPICE simulations and measurement results from a fabricated prototype demonstrating its scope and validity. Finally, a study of finite tracking errors of CCIIs used in the implementation of magneto‐impedance sensor has been realized. Copyright © 2014 John Wiley & Sons, Ltd.     

基于非均匀FDTD混合算法的微带电路电磁耦合分析

微带电路包含微带线以及电路元件等局部精细结构,采用传统的FDTD方法进行电磁波照射PCB板电磁耦合的全波模拟,因网格剖分得很细,导致网格量大,计算效率低下.将非均匀FDTD方法与多网格集总元件FDTD方法结合起来,形成一种新的FDTD混合算法,模拟了电磁脉冲对带有集总元件微带电路的电磁耦合,能够快速计算得到集总元件上耦合产生的瞬态电压和电流响应.通过与有限积分法软件的仿真结果进行对比,验证了该时域混合算法的正确性,并分析了不同电磁脉冲类型以及微带线线间距对微带电路电磁耦合的影响.     

基于PEEC法的发电机定子绕组线棒高频电路模型

建立合理的电机定子绕组电路模型,对于研究定子绕组绝缘局部放电信号的传播规律,了解局部放电信号的特征具有重要意义.部分元等效电路(PEEC)法是基于电磁场方程推导出来的等值电路模型,能够对一些用传统方法难以建模的复杂物理结构建立合理的电路模型,并且所建模型可以方便地与其它模型(比如传输线模型)综合连接、计算仿真,该方法还能够综合考虑外部测量电路的影响,在集成电路高频电路模型建立中有广泛的应用.本文采用PEEC法原理,建立了电机定子绕组单根线棒高频电路模型和双根线棒的耦合传播模型,此方法克服了以往多导体均匀传输线理论在电机定子绕组电路模型建立中的不足.模型中的部分电感、部分电容等参数由PEEC原理结合相关计算软件求得.模型的仿真计算与实验结果比较,证实了所建模型的有效性及参数的准确性.     

含二次项型非均匀传输线网络的灵敏度分析

应用科罗达等效方法可将二次项型无损耗非均匀线用无损耗均匀线及集中参数元件组成的等效电路表示。该文利用伴随网络法和基于科罗达等效的等效电路，提出了二次项型无损耗非均匀线的频域灵敏度分析方法，采用类似拉氏反变换的方法获得了无损耗非均匀线的时域灵敏度公式：以无损耗非均匀线的灵敏度公式为基础，通过集中处理非均匀线的损耗，推导出了二次项型有损耗非均匀线的频域和时域灵敏度公式，为解决求解含这类非均匀线网络的灵敏度提供了一种途径。     

A new combined system of active and passive filters to obtain harmonic compensation for large-capacity thyristor converters

Shunt passive filters, which are connected in parallel to harmonic-producing loads, have been used widely for harmonics suppression in power systems because of low cost and high efficiency. However, they have such inherent problems as series and parallel resonance. On the other hand, shunt active filters, which are also placed in parallel, have such an inherent problem as initial and running costs are high compared with those of shunt passive filters. To solve these inherent problems in shunt passive and shunt active filters, the authors have proposed a combined system of a shunt passive filter and a small rated series-active filter. The purpose of this paper is to reduce the required rating of the series-active filter, considering a practical application of the combined power filter to harmonic compensation for large-capacity thyristor converters. The points are summarized as follows:

• 1 The required rating of the series-active filter can be reduced less than one-tenth by connecting a series-resonant circuit in parallel to the secondary of current transformer.
• 2 It is clarified theoretically and verified experimentally that compensation characteristics of the new combined system are equivalent to those of the already-proposed system with no series-resonant circuit.

     

A Criterion for Performance Comparison Between High Power Inverter Circuits

The efficiency and economics of inverter circuits with high power ratings tend to be determined largely by the size of the passive elements required in the commutation circuit and, to a lesser extent, by the combined current-voltage requirements of the semiconductors. In order to facilitate comparative evaluation of inverter circuits of different configurations which are all candidates for the same application, an analytical expression representative of the total kVA rating of the passive components can be derived for each circuit from the data defining the application. Combining this with a similar expression reflecting the volt-ampere requirements of the active devices, an overall circuit figure of merit can be generated. In certain paper studies, a comparison between such figures of merit can provide a useful, if not infallible, tool for appraising several candidate circuits.     

特高压气体绝缘开关设备套管的宽频等效电路建模

气体绝缘开关设备(GIS)进出线套管处的电磁模型对特快速暂态过电压(VFTO)、暂态外壳电压(TEV)以及外部瞬态空间电磁场的建模计算有重要影响。特高压GIS系统的VFTO频率最高可达100MHz,此时套管屏蔽层导体的长度与电磁波波长可比拟,不能再用集总参数对套管建模。建立了具有双层屏蔽导体的特高压GIS复合套管宽频等效电路,分别采用传输线理论、分段传输线的级联和近似公式建立套管的三导体系统间均匀段、尺寸渐变段的双导体和导体间电磁泄漏阻抗的模型;用集总电容来等效导体尺寸不连续处激发的电磁波的高次模对主模传输的影响;分别提取套管顶部均压环、中间屏蔽层的对地电容,提取套管顶部均压环对中间屏蔽层的部分电容。综合上述传输线及各个部位的阻抗模型,计算1~100MHz频率范围内,从套管底部看进去的输入阻抗,并与全波电磁仿真的套管三维输入阻抗对比,二者一致性较好。     

Some invariant sums of higher‐order sensitivities

In this paper, a new class of invariant sensitivity sums of higher‐order sensitivities is given. Sensitivity sums considered are relevant to a network function of general lumped time‐invariant circuits containing passive and active elements. It is assumed that the circuit is linear and consists of one‐port elements and two‐port elements only. A part of the one‐port elements is described by admittance parameters and the other part by impedance parameters. The rest of the one‐port elements are independent sources. Two‐port elements are only controlled sources. Hybrid matrix should describe functional relationships of the elements. Formulas for invariant sums of sensitivities of first, second, third, and fourth order are presented. Copyright © 2008 John Wiley & Sons, Ltd.     

Application of the partial element equivalent circuit method to tower surge response calculations

This article presents calculations of tower surge responses and insulator voltages of an actual transmission tower including ground wires and phase wires. The partial element equivalent circuit (PEEC) method is applied as a simulation tool. Surge responses of the tower and insulator voltages calculated by the PEEC method are compared with electro magnetic transients program (EMTP) simulated results and experimental results collected from the literatures. The results calculated by the PEEC method agree well with the experimetal results, not only amplitudes but also waveshapes. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

输电线路分布参数测量方法的改进

输电线路参数的精确度对电力系统潮流稳定分析、保护整定、故障定位等至关重要。针对传统的单回输电线路参数测量方法的存在问题,基于线路分布参数模型和等效π电路集中参数模型,推导出输电线路分布参数、等效π电路集中参数、以及短路阻抗与开路阻抗之间的数学关系,实现了线路的分布参数和等值π电路的参数的精确求解,并以算例将所提出的方法与传统方法计算结果进行了对比。     

NEW INTEGRATED SIMULATION TECHNIQUES FOR THE ELECTROMAGNETIC ANALYSIS OF MICROWAVE CIRCUITS USING THE TLM METHOD

A new methodology is presented which allows the integration of lumped elements into electromagnetic simulations, using the TLM method. It is shown that the new method retains the symmetrical condensed node algorithm structure, with the potential to be applied to all lumped elements. A new and accurate method for the extraction of circuit parameters from the impulse response of the TLM method is also presented. The method is simple and can be used for waveguide and planar structures. A study is carried out on the applications of various data windowing techniques during the postprocessing stages of an electromagnetic analysis. This has resulted in the realization of the need for careful selection of a particular window profile, according to the application and the nature of the required results.     

变压器绕组的特快速暂态建模

为了研究陡波前过电压对变压器的影响,从短路导纳参数出发,提出了一种建立变压器绕组高频集中电路模型的方法.该方法首先由短路导纳参数计算绕组各匝的电压传递函数,并利用矢量匹配法对得到的电压传递函数进行有理函数逼近;其次,对得到的有理函数形式的传递函数利用多点Pade逼近进行阶数缩减,得到变压器绕组电压传递函数的降阶模型;最后,运用网络综合技术建立变压器绕组的高频电路模型.该电路模型仅由R、L、C和理想变压器构成,其模型参数可以根据电压传递函数的极点和留数非常方便地得出.通过对电路模型的仿真结果与实际测量结果进行比较,验证了本文方法的正确性.     

铜电解整流装置用并联混合型有源电力滤波器

为解决铜电解装置运行时产生的电网谐波污染和低功率因数问题,提出了在10kV侧安装并联混合型有源电力滤波器进行谐波抑制和无功补偿的综合补偿方案并介绍了混合滤波器的系统构成,混合型有源滤波器的无源部分由滤除11、13次谐波,同时补偿无功功率的11、13次两个无源支路构成。有源部分采用注入式拓扑结构,用来动态滤除11、13次以外的其它次谐波。有源部分对改善无源部分的滤波性能和抑制无源部分与系统等效阻抗之间的谐振发挥了重要作用。给出的现场运行结果表明:研制的并联混合型有源电力滤波器能有效的抑制谐波和进行无功补偿。     

无功补偿和混合滤波综合补偿系统及其应用

提出了一种具有功率因数校正、滤除谐波电流和抑制谐波谐振的电力系统综合补偿系统电路结构并将其成功应用于实际工程。无源支路在补偿无功功率的同时还可以滤除因非线性负载产生的特征谐波电流。为了抑制无源支路跟电网等效电感产生的谐振以及改善无源滤波器的滤波性能，系统中采用了谐振注入式有源滤波拓扑。论文对综合补偿系统的稳态补偿性能进行了详细的分析，并给出了系统的现场运行结果。理论分析和系统的现场运行结果证明了综合补偿系统的有效性和可行性。     

电容式电磁炮电源电路的设计与仿真

通过对脉冲功率电源电路参数和电磁炮参数的分析,建立了两者之间的关系方程并对电源电路进行了设计。通过对典型实例的仿真,验证了电路的可行性。计算和仿真结果表明,采用多组脉冲功率电源驱动电磁炮,能够获得较为理想的弹丸出膛速度。     

Near-field direct antenna modulation

Modern silicon-based technology processes have opened a plethora of opportunities for designing highly integrated millimeterwave systems by providing transistors with cutoff frequency, fT, of more than 200 GHz [1]-[5]. At millimeter-wave frequencies, the wavelengths are comparable to the die size, and this inspires the integration of the radiating elements and active circuit components on a single silicon die. Although integration of millimeter-wave systems on a silicon substrate lowers the cost and improves reliability, there are several challenges that must be addressed appropriately [1], [2]. Because of constraints imposed by the fabrication of active components, the substrate resistivity of the silicon substrate has to be very small (∼1?10 Ω cm). This low resistivity causes energy loss into the substrate and lowers the quality factor Q of unshielded on-chip passive components such as inductors, transmission lines, and antennas and hence results in the degradation of power efficiency and noise performance. The finite conductivity of metal structures causes further energy loss in integrated systems. Since the skin depth becomes very small at millimeter-wave frequencies (e.g., the skin depth of copper at 60 GHz is approximately 300 nm), the ohmic loss in metal structures significantly increases, degrading the performance of passive devices.     

光伏经多端柔性直流输电并网的控制研究

为解决大规模光伏电站远距离输电问题,采用光伏电站接入基于直流电压-有功功率-交流电压控制的多端柔性直流输电系统的并网方案。利用Matlab/Simulink仿真软件构建了一个包含两座光伏电站和一个无源网络的五端柔性直流输电系统模型,并对该系统的运行特性进行了详细的仿真分析。仿真结果表明,当光伏电站的输出功率发生波动时,五端柔直系统传输的有功功率可实现自动平衡;当电网发生三相短路故障时,光伏电站依然能够稳定运行,具有较好的故障穿越能力。