一起SB6型断路器低气压报警事故分析处理过程

SB6型断路器的结构原理较为独特,具有高、低压两个气室,且操动机构在本体内,使其安装、调试和维护与其它SF6断路器有所不同。为了更好的了解和熟悉该类型断路器,介绍了一起SB6型开关低气压报警事故分析处理过程,给出SB6断路器在检修中分析方法及处理思路。对该类断路器正确的维护提供很好的参考。     

Making Engineering Education "Active"

Active education might be defined as a system of instruction in which the student himself plays an active role in his education. The author expresses a certain number of suggestions, mostly based on his experiences, in order to help the achievement of active education in engineering. Theoretical lectures should raise active discussions, comparisons, and applications of theories; approaches different from those traditionally pursued are thus required for carrying out class work and for evaluating students. Applied research in universities should be primarily aimed at attaining educational goals; improving quality of instruction, obtaining the active participation of students in their education, stimulating a professional interest, making them aware of society and its problems. The last-mentioned objective might be easily achieved in communities of few natural resources in a developing country. Suggestions are made for obtaining a profitable use of the time to be dedicated to graduation thesis and for organizing in effective ways, works of students in laboratories. Finally, it is emphasized that experiences of students in industries, carefully organized, can help to make an active education as earlier defined. Furthermore, field experiences can serve to orient the students on their work aptitudes as well to enhance their knowledge of social environments.     

Collapse of MOSFET drain current after soft breakdown

Gate-oxide soft breakdown (SB) can have a severe impact on MOSFET performance even when not producing any large increase of the gate leakage current. The SB effect on the MOSFET characteristics strongly depends on the channel width W: drain saturation current and MOSFET transconductance dramatically drop in transistors with small W after SB. As W increases, the SB effect on the drain current fades. The drain saturation current and transconductance collapse is due to the formation of an oxide defective region around the SB spot, whose area is much larger than the SB conductive path. Similar degradation can be observed even in heavy ion irradiated MOSFETs where localized damaged oxide regions are generated by the impinging ions without producing any increase of gate leakage current.     

Creating a sense of "Presence" in a web-based PSI course: the search for Mark Hopkins' log in a digital world

The technical term presence concerns the feeling that a student is in a real classroom, in real time, with a real person managing the learning. This paper considers the two major factors affecting presence: 1) the choice of pedagogical strategy and 2) its implementation using a freshman computer course taught over the Web by the Personalized System of Instruction (PSI) method. Special attention is paid to the location of professor, proctor, and students in this study as well as other strategies to heighten a sense of presence in Web-based courses.     

"Hands-On" Microprocessor Education at the University of Rhode Island

This paper documents the impact of microprocessor technology on electrical engineering education at the University of Rhode Island. Originally introduced as a method of giving computer experience to a larger number of students, it has become a key element in the undergraduate curriculum. "Microprocessor Laboratory" emphasizes hands-on experience by making computers available for "checkout" use at home. It is introduced as a required course at the sophomore level and the textbooks used are manufacturers' manuals. We employ a series of nine basic exercises and couple these to an end-of-semester project. The course is offered each semester and attracts students from other engineering disciplines and from other colleges within the University. It has been successfully adapted to a five-week summer session and a four-day short course for engineering faculty. The course forms the basis for introducing microprocessors into other, more advanced engineering courses.     

EIC volunteer profile

John has been active with the Electrical Insulation Conference (EIC) since 1995, when he attended his first EEIC/EMCW Expo in Chicago. At the time, he was an industry manager for the National Electrical Manufacturers Association (NEMA) and its Insulating Materials Section. In 1996, John began working directly with EIC volunteers as he assumed the position of Secretary/Treasurer to the EIC Board of Governors, a position he still holds. As the Secretary/Treasurer, he has been responsible for recording all of the meeting minutes of the EIC Board of Governors (1996?present) and EIC/EMCWA Joint Management Committee (1996?2007). He also holds the position of Treasurer of the EIC Board.     

10kV箔式绕组变压器产品简介

概述了ＳＢ８型、ＳＢ９型三相油浸箱式绕组变压器性能和结构特点,并就其经济性和优势进行了比较分析。     

Robustness study of ECG biometric identification in heart rate variability conditions

Electrocardiogram (ECG) has been actively proposed as an aliveness biometric for years. In realistic application, this type of biometrics still needs to be verified in some conditions related to the practical use. Therefore, we propose in this paper the study of two themes that concern its realistic application. First, the single beat of an electrocardiogram (SB‐ECG) is used as the ECG feature, which aims to decrease the time to acquire the ECG from the individual. Second, for the robustness study of ECG features to heart rate variability (HRV), we investigate the relation between the correct identification and the HRV conditions. The HRV‐ECG data is set up and collected by using the Bio‐Pac system. The overall processes of the proposed method are the following: Continuous wavelet transform (CWT) is used to analyze each SB‐ECG. Then the root‐mean square (RMS) value of total energy of the wavelet coefficients of each P, QRS, and T segment is calculated. Next, the Fisher linear discriminant analysis (FLDA) is applied to all sets of the RMS value for dimension reduction. Lastly, the normalized Euclidean distance is implemented as the classifier. The experimental results demonstrate that, with the proposed method, the classification achieves 97% accuracy and the robustness study achieves over 80% accuracy with HRV‐ECG change up to 20%. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Effective Ozone Generation With a Wire–Wire-Type Nonthermal Plasma Reactor With a Slit Barrier

The corona discharge and ozone generation characteristics of a wire–wire-type nonthermal plasma reactor (PR), with a slit dielectric barrier, have been experimentally investigated. When a slit mica barrier is installed between corona wires, a significant increase in the generation of ozone could be obtained. From the photographs of the corona discharges, this type of nonthermal PR with a slit barrier (SB) produces two corona discharges, one from the corona wires and another from the slits of the SB. This second corona discharge is caused by the rapid relaxing of the charges, which are migrated from the corona wire and stored on the surface of the barrier, through the slits. As a result, the proposed nonthermal PR has the potential to significantly increase ozone production, and it may be useful as an effective means for removing pollutant gases.      

Comments on "Deficiencies in the way scattering parameters are Taught"

Equivalent representation of multiport circuits by the use of scattering parameters is of fundamental importance, especially in the microwave circuits area. However, in most cases, only a few pages of textbooks are devoted to this topic; based on the author's experience, the students find it somehow difficult to understand the physical meaning of scattering parameters (while they find other representations, like Z, Y, hybrid, or transmission parameters, easy to understand). For this reason, the contribution given by Sadiku (IEEE Trans. Educ., Vol. 46, no. 3, Aug. 2003, pp. 399-404) is very important. Furthermore, in Sadiku's paper, three nontrivial examples are reported, through which the students can gain understanding of this fundamental tool. In two of the three examples, some points are unclear; this correspondence analyzes this lack of clarity.     

EVAWEB: A Web-Based Assessment System to Learn X.509/PKIX-Based Digital Signatures

EVAWEB is a Web-based assessment system that has been developed to evaluate the learning enhancement produced by the use of X.509 Public Key Infrastructure (X.509/PKIX)-based digital signatures in a real environment. EVAWEB allows the students to experience main X.509/PKIX processes related to the digital signature mechanism. In this paper, EVAWEB and its assessment by the students are described     

一种新型的基于D状态观测器的永磁同步电机无传感器驱动向量控制方法

本文提出了一种新的能用于凸极和隐极永磁同步电机无传感器向量控制方法。这种方法通过一种新型改进的磁链状态观测器来估计转子磁链相位,用于永磁同步电机无传感器向量控制,该状态观测器被称做D状态观测器。D状态观测器有以下几个很具吸引力的特征：1)建立电机数学模型不需要额外的稳态条件；2)它的维数为最小的二维；3)在较宽的运行范围内,唯一一个观测器增益为常量,容易设计；4)以一种非常简单的方式应用电机的参数；5)结构非常简单因而能在较低的计算量下实现。通过广泛的实验验证了该方法的有效性。     

New "D-State-Observer"-based vector control for sensorless drive of permanent-magnet synchronous motors

This paper proposes a new sensorless vector control method that can be applied to both salient-pole and nonsalient-pole permanent-magnet synchronous motors (PMSMs). The proposed method estimates phase of rotor flux by a newly developed flux-state observer for sensorless vector control of PMSMs, which is referred to as the "D-state observer". The D-state observer has the following attractive features: 1) it requires no additional steady-state condition for the motor mathematical model; 2) its order is the minimum second; 3) a single observer gain is simply constant over a wide operating range, and easily designed; 4) it utilizes motor parameters in a very simple manner; and 5) its structure is very simple and can be realized at a very low computational load. Usefulness of the proposed method is examined and confirmed through extensive experiments.     

A pearl of wisdom

Eight years ago, a scant four active members founded the Alexandria University Student Branch (SB) in Egypt. Their modest goal back in 2000 was to start on-campus technical workshops and mini-courses, focusing on electronic circuits, as means of providing the necessary hands-on experience to fulfill a dearth of lab work in their college courses. In other words, bring the IEEE SB polish to the city dubbed "the pearl of the Mediterranean."     

Senior design for persons with disabilities

This article provides an overview of senior design in the United States and its impact around the world. Within the United States, the National Science Foundation (NSF) Senior Design Projects to Aid Persons with Disabilities program has provided funding since 1988 to thousands of senior design projects that have been completed by students for persons with disabilities. This program combines the academic requirement of a design experience with enhanced educational opportunities for students, and it improves the quality of life for disabled individuals. Also described are two national design competitions hosted by the Rehabilitation Research's Rehabilitation Engineering Research Center (RERC) on Accessible Medical Instrumentation (AMI) and the National Collegiate Inventors and Innovators Alliance (NCIIA). In addition, there are a number of biomedical engineering (BMH) programs in the United States that provide an opportunity for students to design and construct projects for individuals in developing countries.     

Undergraduate Instruction in Bipolar Integrated Circuit Design and Fabrication Using "Masterslice" Integrated Circuits

Few undergraduate students have the opportunity for actual laboratory experience fabricating solid-state devices. In this paper we describe the integrated circuit fabrication technique used in our undergraduate integrated electronic circuit design course which allows students to not only learn the theory of integrated circuit design but to actually implement their own designs as integrated circuits; all in a one-quarter three-credit course. Thus, valuable industrially relevant experience is obtained by these undergraduate students at a reasonably low cost to the department.     

Effects of winding connections on characteristics of a five‐phase stepping motor

A method for calculating the single‐step response of five‐phase hybrid stepping motors is obtained. The effects of winding connecting methods—(1) star‐bipolar SB, (2) pentagon PD, and (3) new pentagon NP—on the single‐step response are investigated. By application of the above calculation method, the continuous rotating characteristics are studied. It is found that the maximum slewing pulse rate of NP is higher than that of SB and PD connections, and that the variation of the rotor speed at high speed with the SB and PD connections is larger than that with the NP connection. The effects of the current waveform on the oscillation characteristics and relations between the current waveform and the winding connections are investigated. © 2001 Scripta Technica, Electr Eng Jpn, 136(1): 47–56, 2001     

DataFed: An Architecture for Federating Atmospheric Data for GEOSS

DataFed is a distributed web-services-based computing environment for accessing, processing, and rendering environmental data in support of air quality management and science. The flexible, adaptive environment facilitates the access and flow of atmospheric data from provider to users by enabling the creation of user-driven data processing value chains. The approach of DataFed is mediation between users and data providers. DataFed non-intrusively wraps datasets for access by standards-based web services. The mediator software, composed of web services, provides homogeneous data views (e.g., geospatial, time views) using a global multi-dimensional data model. Application software written using web services are data browsers, including Google Earth, and analysis tools for distributed AQ data. Its federated data pool consists of over 100 datasets and the tools have been applied in several air pollution projects. From the point of view of GEOSS, DataFed contributes air quality data (as services) to the shared data pool through the GEOSS Common Infrastructure. It also hosts a Decision Support System (DSS) in the societal benefit area of air quality. The developers of DataFed actively participate in the GEOSS process included work with Architecture and Data Committee (ADC) and the User Interface Committee (UIC) as well as in interoperability experiments.      

基于楼宇分布式能源提升配电网韧性的智能表计优化配置方法

针对现有配电网韧性研究未充分考虑需求侧资源价值的问题,提出了一种新的利用需求侧智能楼宇(smart building,SB)实现供电韧性的解决方案。首先,基于SB中能量转换存储设备的可调特性,分析了灾后SB对配电网的能量支撑作用。在此基础上,构建了基于二阶段随机规划的需求侧资源最优开发模型。在充分计及极端天气对电网损伤不确定性影响的基础上,以系统投资运行费用及灾后负荷损失成本综合最小作为目标,通过优化智能能量表计在SB用户中安装位置,实现对需求侧分布式能源在灾后负荷恢复中的贡献作用。最后以我国东部某沿海城市实际配电网为例,分析了基于SB供能系统提升配电网韧性的效果及成本效益,并验证了所提方法的有效性。