交-交变频同步电机调速系统的实验仿真研究

利用交-交变频同步电机调速系统原理,采用PSIM软件建立了气隙磁场定向控制的交-交变频同步电机调速系统的仿真模型,对系统模型进行了仿真测试,验证了该模型的稳定性。结合实际热连轧过程,对交-交变频同步电机系统注入电网的谐波进行研究,得到交-交变频同步电机系统运行时谐波的变化规律及其影响因素。实验结果表明,仿真波形变化与现场的波形变化基本相同,该模型可辅助相关理论研究。     

IGCT交-直-交变频调速技术在本钢1700热轧机组的应用

文章简要叙述了本钢1700热轧机组主传动采用的美国GE Innovation Drive系列高压大功率交-直-交变频调速系统的构成及特点,定性地介绍了本系统采用的三电平PWM变频调速的基本原理和组成以及在本钢1700热轧机组的实际应用。     

交-交变频器双闭环调速系统自适应模糊控制仿真

文章首先给出交一交变频器双闭环调速系统的原理框图,然后使用MATLAB／Simulink软件对交一交变频器双闭环调速系统的自适应模糊控制方式进行了仿真,指出自适应模糊控制优于PI调节控制。     

无刷直流电机闭环调速实验装置的建模与仿真

以无刷直流电机闭环调速实验装置为研究对象,分析了无刷直流电机控制特性,结合传感器技术给出了转速单闭环和转速电流双闭环2种调速控制策略,分别建立了2种调速系统的Simulink模型并进行了仿真比较。结果显示:2种调速系统都具有良好的动态响应和抗扰动性能。在突加负载的情况下,双闭环调速系统比单闭环调速系统对电流转矩的响应更快且波动超调较小,虽然电机转速落差较大,但总体性能较优。     

单片机控制的三相电压型交-交变频器

介绍一种单片机控制的三相电压型交-交变频器，论述了交-交变频器的系统组成、控制方案及有关难点问题的解决     

单片机控制的三相电压型交—交变频器

介绍一种单片机控制的三相电压型交-交变频器，论述了交-交变频器的系统组成、控制方案及有关难点问题的解决。     

浅谈变频及脉冲调速技木在煤矿的应用

随着交流变频调速技术的日益成熟并应用于生产中,交流电机和直流电机相比具有功率大、效率高、无电刷和换向器,维护成本小的优点,因此,在煤矿生产运输上广泛使用已经成为发展的趋势.本文结合煤矿运输主要设备情况,分析了变频及脉冲调速技木在煤矿的应用及节能效果.     

基于Matlab/Simulink交-直-交调控系统的建模与仿真

利用Matlab/Simulink构造交—直—交调速系统的仿真,仿真系统采用Simpowersystems和Simu-link模块化设计,并增设示波器,观察系统参数变化对系统的影响,利用仿真结果来指导系统的调试安装,据此设计出优化高效的调速方案。     

132KW无换向器电动机调速系统(TDS)浅析

本文时引进的合成氨装置汽化炉渣油泵无换向器电动机及其调速系统，针时其调速系统的整体进行浅析．以期时该系统作一原理性的解读。     

基于交-交变频技术实现异步电动机重载起动的研究

为解决异步电动机重载起动存在的不足,提出了一种以80C196KC DSP为控制技术的交-交变频系统的实现方法.该方法具有起动电流小、启动转矩大、启动平滑、运行稳定、控制效果好的特点,详细阐述系统主电路及控制部分的原理和实现方法.     

Total Quality Management in Engineering Education—A Case Study from University College Dublin (National University of Ireland-Dublin)

The last 3 years have seen extensive time and resources invested in quality assessment/quality improvement (QA/QI) within the Irish university sector. The introduction of a formalized QA/QI programme in the 1998/99 academic year at University College Dublin (UCD) of Ireland-Dublin, will mean that every department in College will have a direct and compulsory involvement in the quality assurance programme in the coming years. There is limited experience of formalized quality assessment in the higher education sector in Ireland, and several pilot projects have been running which represent a first step in establishing a methodology suited to conditions prevailing within the Irish context. The Universities Act 1997 in Ireland will drive the issue of quality assessment in the university sector and ensure that emphasis is placed on the attainment of the highest possible standards in teaching and research. The universities are responding to this new challenge by adopting a pro-active approach and implementing the QA/QI schemes as a matter of some urgency. This paper outlines details of key pilot projects undertaken in recent times.     

Development of Long Live Love+, a school-based online sexual health programme for young adults. An intervention mapping approach

This paper describes the development of a Dutch online programme called Long Live Love+ focusing on positive, coercion-free relationships, contraception use, and the prevention of STIs, using the Intervention Mapping (IM) approach. All six steps of the approach were followed. Step 1 confirmed the need for a sexual health programme targeting young people aged 15 and over enrolled in higher level secondary education. Step 2 resulted in the production of a series of matrices-of-changes, including detailed programme objectives at the behavioural and the psycho-social level. Step 3 involved the selection of relevant methods and applications. Step 4 consisted of programme development, resulting in a sexual health programme with online and offline components, and including interactive exercises. Step 5 focused on adoption and implementation and included the production of a detailed teacher manual. Step 6 involved detailed planning for the process and effect evaluation and included interviews with teachers and focus group discussions with students to evaluate their experiences of the programme. The inclusion of a linkage group – and especially the inclusion of teachers in the development of the programme – turned out to be essential in terms of developing a programme in line with their context and needs.     

Professional development of Russian HEIs' management and faculty in CDIO standards application

The paper presents the approach to complex training of managers and faculty staff for system modernisation of Russian engineering education. As a methodological basis of design and implementation of the faculty development programme, the CDIO (Conceive-Design-Implement-Operate) Approach was chosen due to compliance of its concept to the purposes and tasks of engineering education development in Russia. The authors describe the structure, the content and implementation technology of the programme designed by Tomsk Polytechnic University and Skolkovo Institute of Science and Technology with the assistance of Chalmers University of Technology and KTH Royal Institute of Technology and other members of the CDIO Initiative. The programme evaluation based on the questionnaire results showed that the programme content is relevant, has high practical value and high level of novelty for all categories of participants. Therefore, the CDIO approach was recommended for implementation to improve various elements of the engineering programme such as learning outcomes, content and structure, teaching, learning and assessment methods. Besides, the feedback results obtained through programme participants’ survey contribute to identification of problems preventing development of engineering education in Russia and thus serve as milestones for further development of the programme.     

A Masters Programme in telecommunications management – demand-based curriculum design

This paper presents a curriculum design approach for a Masters Programme in Telecommunications Management based on demand data obtained from surveying the needs of potential students of the proposed programme. Through online surveys disseminated at telecom companies in Jordan, it was possible to measure the demand for such a programme and to determine the required programme contents and specifications. The curriculum design is based on definition of programme outcomes and on using a house of quality approach (HOQ) to determine the list of courses required in the programme. Surveyed competencies are mapped to a long list of proposed courses in a HOQ in order to determine the importance of each of these courses. A final list of core and elective courses is then developed considering the contribution to programme outcomes and the academic standards.     

Managing to make a difference

This is an account of a programme involving the application of action learning to the task of ‘blending personal development with development of an organisation's capability’. It was aimed at dismantling cross boundary barriers and extending cross boundary networks. It became clear that staff needed to reflect on their own effectiveness in current roles and, despite considerable ongoing change, begin to drive their own development in the organisation. The changes also demanded that they extend their knowledge and skills in confronting and solving problems. The programme designed to achieve these aims proved to be highly successful.     

Philosophical education and cultural relevance: discipline-affirmation in the context of the knowledge economy

The following paper proposes a discipline-affirming response to the challenge facing higher education in the context of the knowledge economy. It resists the drive to reduce the value of a humanities based education to the mere production of skills and instead affirms the substantial body of knowledge of specific disciplines. It uses as its model the degree programme in Philosophical Studies at Newcastle University in order to show how a discipline-affirming approach to learning has the advantage of not only developing and making students aware of educational skills that can contribute to the knowledge economy, but doing so without downgrading the worth of the knowledge and concepts of the students' discipline. The aim of the present paper is to demonstrate that a learner involved in a personalised, object-based project will not view the acquisition of knowledge as merely a means to an end and also be able to communicate the value of the knowledge gained to laypeople.     

Teacher perspectives on factors facilitating implementation of whole school approaches for resolving conflict

While social–emotional learning programmes in schools often have positive outcomes, many such initiatives are not well implemented and maintained. This paper reports on teacher reflections on the process of planning and implementing a whole school social–emotional learning (SEL) programme with a conflict resolution focus, called Enhancing Relationships in School Communities (ERIS). Ten primary schools participated in an 18‐month professional development programme offered by the researchers to assist schools to develop a whole school approach to handling interpersonal issues using a cooperative problem‐solving approach. Implementation (core) teams of three to five members, including principal or assistant principal and relevant teachers, attended workshops and managed the change process. In individual interviews, 29 core team members described the most significant changes that had taken place, what factors facilitated those changes and what assisted in overcoming barriers. A synthesised model of facilitators of implementation was developed on the basis of these interviews. The major components of the model included ensuring a whole school vision and process; pre‐programme engagement confirming commitment and alignment of researcher and teachers' visions; facilitative programme structure and processes such as linking the current programme to existing programmes and processes in the school; leadership and support for staff in the change process, for example, through the implementation team; the nature of the programme content; and monitoring and feedback processes to sustain motivation and inform on needs and outcomes.     

The effects of guided elaboration in a CSCL programme on the learning outcomes of primary school students from Dutch and immigrant families

This study examined the effects of guided elaboration on students' learning outcomes in a computer-supported collaborative learning (CSCL) environment. The programme provided students with feedback on their elaborations, and students reflected on this feedback. It was expected that students in the experimental (elaboration) programme would show better learning gains and that students from immigrant families would especially benefit. Two hundred primary school students of 9 different schools participated. The research can be characterized as a quasi-experimental study with a pre-test, post-test, control group design. In a multilevel regression analysis, no main effect of the intervention was found. However, there was a significant differential effect of the intervention; students from immigrant families in the experimental programme outperformed their counterparts in the control group. It can be concluded that guided elaboration in a CSCL programme through feedback and reflection is a promising approach.     

Book Reviews

Abstract

This paper examines the current status of inservice education for teachers in Nigeria with particular reference to Cross River and Akwa Ibom States. It identifies three main approaches to teacher inservice education in the two states of Nigeria, viz. the central office approach, the long vacation (sandwich) programme and Associateship Certificate in Education‐‐part‐time evening programme distance learning approach. Inservice teacher education is seen as an effective means of augmenting the inadequacies of pre‐service training. It is a process for continuous updating of teachers’ knowledge, skills and interests in their chosen field. The paper discusses the factors which should be considered when planning and implementing inservice education programme. Some suggestions on how to plan and implement inservice teacher education programmes in Nigeria are given.