Incorporating instructional feedback in electrical engineeringlaboratory experiments-an example

The advantages of incorporating software tools, other than simulation packages, in electrical engineering laboratory experiments are discussed in this correspondence. This approach supports the prerequisite lecture material and allows study and understanding of some practical issues which are best handled through a laboratory experiment. It is also shown that only through software can instructional feedback be easily integrated in the students' work. Time and effort are optimized and difficulties in assimilating the material and correlating the results are minimized. A detailed laboratory experiment, namely performance analysis of an induction motor, which is significantly enhanced with the support of a software package called Mathead, is provided as an example     

面向产消用户的售电公司发-用电多元电力套餐优化EI北大核心CSCD

新型电力系统背景下的产消用户不断发展,这给售电公司在设计多元化套餐吸引产消用户以及利用发电资源方面带来挑战。充分考虑产消用户的发用电特点,提出售电公司面向产消用户的发-用电多元电力套餐优化策略。设计2种发电套餐、3种用电套餐和2种发用电捆绑套餐;分别以考虑风险的售电公司综合收益最大和产消用户的综合满意度最高为目标函数,构建主方的购售电决策模型和从方的套餐选择模型,阐述售电公司和产消用户的主从博弈互动过程;提出博弈过程中的套餐组合策略,以提高套餐的多样性;采用粒子群优化算法和CPLEX优化软件求解模型的纳什均衡解。算例分析结果表明,博弈模型具有较好的收敛性,所提多元发-用电套餐和套餐组合策略能够适应不同类型的产消用户,提高产消用户的综合满意度。     

On Wire Failures in Microelectronic Packages

At present, over 95% of the manufactured packages are still being wire-bonded. Due to the ongoing trend of miniaturization, material changes, and cost reduction, wire-bond-related failures are becoming increasingly important. Different finite-element (FE) techniques are explored for their ability to describe the thermomechanical behavior of the wire embedded in the electronic package. The developed nonlinear and parametric FE models are able to predict the strong nonlinear behavior of wire failures and multifailure-mode interaction accurately and efficiently. It is found that both processing and reliability-testing environments as well as the occurrence of delamination strongly increase the risk of wire failures. Our results indicate that processing and reliability-testing influences are much less than those of the delamination. Combining the strengths of predictive modeling with simulation-based optimization methods, the optimal wire-loop shape is obtained.      

INTEGRATED SOFTWARE FOR OPTIMAL DIRECTIONAL OVERCURRENT RELAY COORDINATION

ABSTRACT

This paper reports the development of fully integrated software for the optimal directional overcurrent relay coordination of interconnected power systems. Different software packages like load flow analysis, fault analysis, determination of backup/primary relay pairs, main relay coordination program, etc. have been integrated. The program could be run as an interactive package or as an off-line package, depending upon the choice of the user. The information needed for the coordination is stored and used by the software. No data base management packages are needed to manage huge data generated by the program. The software uses an efficient method to generate, store and retrieve the data as per the requirements of the coordination. In the Interactive mode, the information about the coordination time interval, range of the relay settings, limits to the maximum and minimum time of operation of the relays, etc., are supplied. All other relevant data needed for coordination are generated by the software package itself. The usage of the program is illustrated by a case study involving the SPC 26-bus power system.     

Teaching nonlinear modeling, simulation, and control of electronic power converters using MATLAB/SIMULINK

This paper describes an efficient method to teach analysis and simulation of power electronic converters to undergraduate students, using system level nonlinear state-space models. System-level modeling of power electronic converters reproduces only the ideal switching behavior of the semiconductors and is a useful concept for the numerical simulation of power converters, since simulations present no convergence problems and require little computational time. Switched state-space models, programmed in the MATLAB/SIMULINK software package, can be advantageously used to simulate power converters at the system level and also to design and study their controllers. Switched state-space nonlinear models should be obtained using a theoretical framework suitable for the enhanced control of variable structure power systems. Since the method is inherently nonlinear, no approximated linear models are needed; and since state-space models are used, modern control techniques (sliding mode, neural networks, fuzzy logic) for power converters can easily be used. This paper summarizes the proposed methodology and gives some examples.     

Computer-aided analog electronics teaching

A computer-aided approach to teaching undergraduate course in electronics is discussed in this paper. It is shown that the symbolic manipulation packages like MAPLE give an additional insight that cannot be obtained by using a numerical simulation package like SPICE. Symbolic manipulation (MAPLE) and numerical simulation (SPICE)-an excellent complementary combination-can enable the students to analyze and understand complicated circuits     

电力电子电路与系统中的复杂行为研究综述

电力电子电路与系统中的复杂行为已经成为近年来电力电子学研究中的一个重要分支,受到了广泛的关注.本文比较系统地介绍了电力电子电路与系统中复杂行为的研究进展,包括这类电路系统的非线性动力学模型的建模方法、分岔产生的机制和通向混沌的道路;讨论了分岔与混沌研究、进行分岔与混沌控制在电力电子电路与系统设计中的实用性和关键性问题;最后,对若干需要研究的问题进行了展望.     

A software tool for learning the dynamic behavior of powerelectronics circuits

A new software tool for learning the dynamic behavior of power electronics circuits is developed for undergraduate students. This tool incorporates the merits of two well-known software packages, namely, the realistic time-domain simulation of PSpice and the parametric identification process of MatLab. Hence, without going through complicated mathematics, the students can easily obtain the transient response, transfer function, and frequency response of power electronics circuits. The software tool is exemplified using a buck DC-DC converter. Its accuracy is verified by comparing the simulation result with those obtained by the state-space averaging technique and the experimental measurement     

A dynamic electro-thermal model for the IGBT

A physics-based dynamic electrothermal model is developed for the IGBT by coupling a temperature-dependent IGBT electrical model with dynamic thermal models for the IGBT silicon chip, packages, and heatsinks. The temperature-dependent IGBT electrical model describes the instantaneous electrical behavior in terms of the instantaneous temperature of the IGBT silicon chip surface. The instantaneous power dissipated in the IGBT is calculated using the electrical model and determines the instantaneous rate that heat is applied to the surface of the silicon chip thermal model. The thermal models determine the evolution of the temperature distribution within the thermal network and thus determine the instantaneous value of the silicon chip surface temperature used by the electrical model. The IGBT electrothermal model is implemented in the Saber circuit simulator and is connected to external circuits in the same way as the previously presented Saber IGBT model, except that it has an additional thermal terminal that is connected to the thermal network component models for the silicon chip, package, and heatsink. The IGBT dynamic electrothermal model and the thermal network component models are verified for the range of temperature and power dissipation levels (heating rates) that are important for power electronic systems     

基于VisSim的快速蒙特卡罗分析方法的实现

由于制造工艺和实际工作环境的影响,实际电子线路中的元器件及输入参数与其标称值之间总是存在着随机误差。在设计高精度的电子线路时,其容差分析就显得非常必要。本介绍了电子线路容差分析的基本原理。VisSim作为一种功能强大的控制系统仿真软件,其自身并不支持蒙特卡罗仿真,本提出了基于VisSim利用动态链接库的技术实现电子线路的快速蒙特卡罗分析方法。通过具体电子线路的分析,结果证明了该方法的可行性。     

Applying IT Tools to a Laboratory Course for Measurement, Analysis, and Design of Electric and Electronic Circuits

The paper presents the application of information technology (IT) tools to a laboratory course for measurement, analysis, design, and simulation of typical electric and electronic circuits. It shows modern computer data acquisition systems used for measurement of real circuits, mathematical software IT tools used for theoretical analysis and design, and circuit simulation software IT tools used for the development of a virtual laboratory. It illustrates how spreadsheets and other IT tools are used for data recording and/or result comparisons among measurement, theoretical calculation, and simulation. The paper shows the mechanisms and approaches developed for strong correlation between theories and hands-on experimentation using modern computer tools for the purpose of quality education of the laboratory course in electric and electronic circuits.     

基于拼图方式的电力电子电机系统通用仿真软件包

在综合分析,研究了国内外电力电子仿真软件的基础上,结合课题的实际应用背景和现有的工作条件,开发了基于拼图方式的电力电子电机系统通用仿真软件包。     

A new public-domain simulator for power electronic circuits

A new public-domain simulator (SEQUEL) for power electronic circuits is described. The organization of the simulator is briefly discussed. The most important feature of the simulator is that the user can define new elements in a flexible manner. The differences between the new simulator and other simulators are enumerated. Some simulation examples are discussed to demonstrate the applications of the simulator. It is pointed out that the new simulator is particularly attractive for engineering institutes in developing countries where access to expensive commercial packages with similar capabilities may be difficult     

基于BPA和PSASP程序的短路电流计算比对

BPA和PSASP程序是目前国内使用较为普遍的2种短路电流计算程序（使用率在80%以上）,使用这2种程序的计算结果存在较大差异,已影响到电网的决策。结合国内现行的短路电流计算标准,分析研究了基于潮流和基于网络条件下短路电流计算结果存在差异的原因。研究发现,造成计算结果差异的主要原因是缺乏统一的标准,另一个重要原因是计算...     

Development of sequential build-up multilayer printed wiring boards in Japan

Printed Wiring Boards (PWB) made by Sequential Build-Up (SBU) processes have found a wide application in semiconductor packaging substrates and system in package substrates, besides usage as a conventional printed wiring board. Its capability for high density circuits can contain multi-functional electronic circuits within a small surface area and can achieve light weight and low-profile products with improved electric characteristics. A number of processes and materials were developed and are used for each application in each electronic product. The advancement of printed wiring boards is expected to continue, driven by the requirements from electronic products. Technical development activities are needed to satisfy these requirements. Activities are still high in the development of embedded passive technology, which will equip printed wiring boards with the functions of passive components resistance (R), capacitance (C) and inductance (L) - as well as the conventional interconnection functions of conductors between components. This technology will dramatically change the structure of printed wiring boards and complicate the fabrication processes. Material development will be a key issue in the case of embedded resistors and capacitors.     

ACTIVE LINEAR DC CIRCUIT MODELS FOR POWER SYSTEM ANALYSIS

Abstract

The nonlinear equations encountered in steady state and transient analysis of power systems are often linearized for use in iterative methods or small change sensitivity studies such as dynamic stability. In this work, the standard constant power constraints are linearized and represented as active linear DC electronic circuits. The model is an exact small signal representation and maintains the fundamental voltage/current variables in the original nonlinear circuit model. The circuits can be reduced using standard Norton/Thevenin equivalent techniques.     

用于开发车辆MCU的变参数电机硬件在环测试方法

分析了电机驱动控制器硬件在环(HIL)仿真技术的关键点,基于NI平台和OPAL-RT电机和电力电子仿真工具包建立了完整的用于开发、测试和验证车辆微控制单元(MCU)的HIL仿真测试系统,功能涵盖试验配置和管理、模型自定义、非线性特征定义和在线调参等。详细介绍了试验中各部分模型的建立方法。结合电机标定测试工况,分别基于电机定参数模型和变参数模型进行仿真测试。测试结果表明,变参数电机模型的试验结果与真实台架的测试结果近似,误差小于15%。通过软件故障注入功能,方便地实现了功率管失效、桥臂直通和相间短路等电气故障注入测试。     

The EE student's PC tool kit. II. Programs for graphing andplotting

For pt.I see ibid., vol.8, no.3, p.44-8 (1989). Public-domain and shareware application programs useful in electrical engineering coursework are described, focusing on software for graphing and plotting data. The question of graphics compatibility is addressed, and three software packages are described: PC-GRAF, a plotting package intended to produce line graphs on the IBM CGA screen or on a SWEET-P plotter; Mtool, a mathematical tool that can perform several useful functions with respect to an arbitrary well-behaved function of one variable; and CFIT, a program that can be used to try and fit up to 196 different curves to a group of data point pairs by the least-squares method     

考虑用户有限理性的售电公司峰谷组合电力套餐设计

中国电力零售侧市场化程度逐步加深,售电公司须为电力用户提供有针对性的电力套餐以保障其市场占有率和持续盈利能力.为此,提出售电公司峰谷组合电力套餐零售模式并构建了考虑用户有限理性的电力套餐设计双层优化模型.在上层模型中,售电公司以购售电收益最大化为目标优化峰谷电力套餐参数及其在电力市场中的购电策略;在下层模型中,用户以购电综合效用最大化为目标进行峰谷组合套餐定制,考虑了裕度电量价值及从众心理对有限理性用户决策的影响,同时基于锚定效应模拟了用户在选购电力套餐后的用电行为.以某地居民用户为对象进行仿真分析,结果表明售电公司可通过设计峰谷组合电力套餐激励有限理性用户主动调整用电行为,提高购售电收益.     

Second order mem‐circuits

This paper presents a comprehensive taxonomy of so‐called second‐order memory devices, which include charge‐controlled memcapacitors and flux‐controlled meminductors, among other novel circuit elements. These devices, which are classified according to their differential and state orders, are necessary to get a complete extension of the family of classical nonlinear circuit elements (resistors, capacitors, and inductors) for all possible controlling variables. Using a fully nonlinear formalism, we obtain nondegeneracy conditions for a broad class of second‐order mem‐circuits. This class of circuits is expected to yield a rich dynamic behavior; in this regard, we explore certain bifurcation phenomena exhibited by a family of circuits including a charge‐controlled memcapacitor and a flux‐controlled meminductor, providing some directions for future research. Copyright © 2014 John Wiley & Sons, Ltd.