新型电梯曳引机驱动与控制系统设计与实现探讨

电梯是一种特殊的设备,电梯的可靠性与安全性对核心部件曳引机及其控制的要求很高,永磁同步曳引机因为具有优良的控制性能、较高效率以及体积紧凑等特点,因为这些优点的存在,永磁同步曳引机在电梯领域中得到了广泛的推广和应用。本文通过对电梯系统的整体结构进行了阐述,对永磁同步曳引机进行了深入的分析,在文章的最后,对控制系统电路进行了一定的研究,希望可以供相关的研究做一些参考。     

永磁同步曳引机在电梯检验中所遇到的诸多问题

本文从机械特性和电器特性两个方面对无齿永磁同步曳引机在实际应用中存在的种种问题进行了分析,并对与此相关的检验内容提出了自己的看法。     

电梯新技术在电梯选型配置中的应用

电梯新技术在电梯选型配置中得到了广泛应用,特别是国际驰名的电梯企业,如迅达、奥的斯等,这些新技术包括:迅达公司Miconic10目的楼层厅站登记系统,双层轿厢电梯,奥的斯公司Odyssey集垂直运输与水平运输的复合运输系统,交流永磁同步无齿轮曳引机驱动的无机房电梯,彩色大屏幕液晶楼层显示器,电梯远程监控系统.     

电梯检验谜团解开了——赴广州日立学习纪实

作为电梯检验员,我虽然从事电梯检验工作多年,但始终对电梯生产厂家的生产制造、工艺流程、技术性能不甚了解。特别是对曳引机的内部构造只有一些模糊的概念。因为具体的现场检验中,我看到的都是曳引机成品。而在检验规程中也无打开曳引机进行内部检验的具体项目。因此,通常看到的都是外观检验或轴头是否漏缺,油位是否恰当的一般性检查。在现场检验中遇到曳引机漏油严重,异响声刺耳,机     

组合励磁稀土永磁同步发电机的设计研究

稀土永磁发电机是一种结构简单,工作效率高、工作稳定性较强的发电机,在诸多领域都有着极为广泛的应用,但是稀土永磁发电机电压调节困难的问题一直得不到有效的改善,在很大程度上制约了其推广。针对稀土永磁同步发电机存在的调压问题,本研究采用组合励磁的方式在一定程度上解决了其调压问题。本文就简单介绍组合励磁稀土永磁同步发电机的基本结构、工作原理以及其运行的特点,希望能够对广大同行起到借鉴与参考的作用。     

稀土永磁同步电动机

介绍了稀土永磁同步电动机的基本结构、设计特点和优势,并对如何在设计上提高稀土永磁同步电动机效率和起动转矩进行了简单说明。     

永磁同步电动机运动系统控制方案研究

永磁同步电动机常被用来构建高精度的运动控制系统,近年其应用受到广泛关注。本文介绍了永磁同步电动机的结构和工作原理,分析了磁场定向矢量控制方法,提出了永磁同步电动机调速控制系统的控制方案。     

旋转编码器在M瓦级风机中的应用及常见故障

在现代风力发电机组中按发电机不同的发电原理可以分为两大类,一类是双馈机组,一类是距永磁直驱同步发电机组。在现代风机技术不断发展进步的过程中,永磁直驱同步发电机组技术不断成熟,在风力发电领域应用也不断增加。永磁直驱同步发电机组中大多采用电变桨系统,所以旋转编码器成为检测变桨系统叶片角度的重要元器件。本论文主要介绍了旋转编码器的作用,在风电场现场有关旋转编码器多种故障的原因,以及处理办法。     

直驱式永磁同步风力发电系统控制研究

伴随着世界经济的不断发展,给能源和生态造成了巨大的压力。近年来,随着人们思想意识的不断提高,人们开始开发新的可替代能源。在一系列新能源的开发过程中,风能以其较大的规模和快速的发展速度引起了人们的瞩目。随着风能的不断开发,出现了多个靠风力来进行发电的系统,而在这些系统当中,最具特点和效率最高的是直驱式永磁同步风力发电系统。采用直驱式永磁同步风力发电系统给人们带来了更高的效率,其自身拥有简单的结构和较大的可靠性,对直驱式永磁同步风力发电系统的控制研究越来越受到重视。     

无机房电梯开发简况

自上世纪90年代中期以来,由于电梯驱动与控制技术的发展,特别是坚固、耐用、高效的永磁同步电机曳引机的开发成功,无机房电梯市场化的进程大大加快。世界上各大电梯制造厂商相继将新型的无机房电梯(以下简称MRL电梯)产品推向市场。一、无机房电梯技术发展动态1.MRL电梯的驱动方式从驱动系统看,MRL电梯除了液压驱动方式外,还有下列几种方案。(1)交流感应直线电机驱动,传统的旋转电机,当其直径为无穷大时即成为直线电机。采用直线电机驱动电梯上下运行,不像传统的电梯驱动那样把曳引机的旋转运动变换成轿厢的直线运动,从而省掉了机房。这…     

Development in Information and Communications Technology (ICT) Statistics at the Australian Bureau of Statistics

This paper outlines the ICT statistical developments that the ABS has undertaken over recent years. These developments have been on both the supply side (ICT industry) and the demand side (use of IT by sector). The content of ABS ICT surveys has changed significantly over the last few years and are expected to develop further in line with industry changes and emerging policy needs.
Recent developments in household collections have been the inclusion of IT use questions in the 2001 Census of Population and Housing and in various ABS social surveys such as Children's Participation in Culture and Leisure Activities. Annual business IT use surveys are now conducted and include topics such as Internet commerce and IT security. Biennial ICT industry surveys are conducted to provide data on ICT production, imports and exports, ICT industry employment, performance and structure information. An Internet activity survey is run every six months and provides regional Internet access details and infrastructure details on Internet service providers.
A major development for 2002–03 will be the compilation of an ICT satellite account. ABS intends to produce an ICT Information Development Plan to guide its future statistical development work in the ICT field.     

Incumplimiento del salario mínimo en Europa central y oriental

En este estudio se analiza el incumplimiento del salario mínimo durante el periodo 2003–2012 en diez países de Europa central y oriental con salario mínimo obligatorio nacional. A partir de los datos de EU‐SILC y la metodología propuesta por Bhorat, Kanbur y Mayet (2013), se cuantifica la incidencia y magnitud del incumplimiento. Se realizan análisis de regresión sobre determinantes individuales, laborales y macroeconómicos. Aunque la incidencia permanece relativamente baja, los trabajadores a los que se dirigen las políticas de salario mínimo parecen los más expuestos a su incumplimiento. Con el tiempo, una mayor incidencia se asocia a una razón más alta entre salario mínimo y salario medio.     

Value at Risk in the Suburbs: Eminent Domain and the Geographical Politics of the US Foreclosure Crisis

Several US counties and local governments have recently considered a novel solution to the foreclosure crisis. They plan to use eminent domain to compel the owners of mortgage debt—and specifically of private‐label mortgage‐backed securities—to sell the debt to the government at a price reflecting the loan's market value. The government would then restructure the debt and resell it to new investors. The plans are striking because—in contrast to both development‐driven eminent domain and the federal subprime bank bailout—they would force investors to assume asset devaluation and increased long‐term risk. Notably, the plans have emerged as an instance of financialization‐focused politics in suburbs and suburban cities of color, specifically majority‐black and ‐Latino/a suburbs. Local support for the plans, we argue, is rooted in the long‐term disinvestment of these ‘suburbs of exception', which became targets of subprime lending and eventually sites where the ‘financial exception' has been localized. But these demographic shifts, fragmentation and fiscal pressures have at the same time created a suburban political terrain in which the plans have gained their strongest political support.     

Towards a Theory of Serendipity: A Systematic Review and Conceptualization

Serendipity – the notion of making surprising and valuable discoveries – plays a major role in the success of individuals and organizations alike. Previous research has established the importance of serendipity and identified important individual- and organizational-level antecedents. However, the literature has been dispersed and the boundaries of the concept have been blurry, leading to a lack of conceptual clarity and structure, and thus limiting validity and managerial actionability. Based on a systematic literature review, I synthesize existing management-related research on serendipity and explicate the emergence and composition of serendipity in the organizational context. I first identify three necessary conditions that differentiate serendipity from related concepts such as luck or targeted innovation: agency, surprise, and value. Then, I draw from the literature on sensemaking, event-based theorizing, and quantum-based approaches to management to conceptualize the process of cultivating serendipity in the organizational context as a process of enabling potentiality and materialization, and develop a multi-level theory of (cultivating) serendipity. This conceptualization contributes to our collective understanding of how, why, and when (i.e., under what conditions) organizations can leverage the value in the unexpected, which opens up fruitful avenues for further research.     

Accountability of NGOs in Bangladesh A critical overview

NGOs in Bangladesh have been recognized as effective change agents in the socio-economic arena throughout the world. Their contributions in micro credit, non-formal education and primary health care are widely known. NGOs play a significant role in society. NGO accountability, as a result, has become a critical issue. NGO accountability in Bangladesh has been examined here in relation to patrons, clients and themselves. Of the three relationships only accountability to patrons is in a near satisfactory state. Accountability to clients is handicapped by lack of opportunities of beneficiaries to participate meaningfully in NGO policy making. Accountability to themselves is adversely affected due to the adherence to a strictly hierarchical system and the influence of founding and charismatic NGO leaders.     

Ansätze und Ergebnisse anglo-amerikanischer M&A-Forschung

Based on a review of established U.S. management journals (1995–2003), six schools of thought are identified within the Anglo-American M&;A research: “Capital Market”, “Principal/Agent”, “Industrial Organization”, “Organizational Behavior”, “Human Resources” and “Strategic Management”. The literature review shows that the definition of M&;A success, the methods applied, and insights from empirical research differ according to the respective school of thought. Empirical studies focus on the resource combinations of merger partners, the specific circumstances of merger negotiations, and on integration management as antecedents of merger performance. Unfortunately, empirical findings have not yet provided reliable explanations for M&;A success. Based on the current state of Anglo-American M&;A research, the authors discuss implications for business practice, identify research gaps, and propose areas for future research.     

Towards an Asian model of human resource management? A comparative analysis of China,Japan and South Korea

There has been much discussion regarding the possible decline and weakening of national systems of human resource management (HRM). Yet, culture and institutions are often cited as the major stumbling blocks to this outcome. Such constraints may dissipate in the analysis, particularly if ‘regional clusters’ are considered where geographic and cultural closeness and ‘openness’ to similar economic pressures exist. In such cases, it might be postulated that convergence in HRM will occur. We argue that China, Japan and South Korea represent such a cluster. This article examines these countries, to see if a degree of convergence is taking place and if it is towards an identifiable ‘Asian’ model of HRM. A model of change is presented that distinguishes between levels of occurrence and acceptance. Details of the development and practice of HRM in each country are then set out. The article ends with a discussion and implications section and a brief conclusion.     

Cultural Economy Planning in Creative Cities: Discourse and Practice

While a growing body of research analyses the functional mechanisms of the cultural or creative economy, there has been little attention devoted to understanding how local governments translate this work into policy. Moreover, research in this vein focuses predominately on Richard Florida's creative class thesis rather than considering the wider body of work that may influence policy. This article seeks to develop a deeper understanding of how municipalities conceptualize and plan for the cultural economy through the lens of two cities held up as model ‘creative cities’ — Austin, Texas and Toronto, Ontario. The work pays particular attention to how the cities adopt and adapt leading theories, strategies and discourses of the cultural economy. While policy documents indicate that the cities embrace the creative city model, in practice agencies tend to adapt conventional economic development strategies for cultural economy activity and appropriate the language of the creative city for multiple purposes.     

Introduction of New Technology with a Sound Transition of the Input-Output Structure

We examine the general equilibrium repercussions associated with the introduction of new technologies, using the generalized Leontief system that allows technological substitutions. We show that an untested introduction of cost-increasing technologies in any industry may result in creating a non-productive technological structure that does not satisfy the Hawkins-Simon condition, following the autonomous dynamic adjustment process with structural transitions in the economic system. Therefore, we propose a practicable control scheme of introducing cost-increasing technologies that strictly avoids the creation of non-productive structures in all periods of structural transition, using the available information on the ex ante technological structure.     

Input/output ranges and performance: an examination of US machine tool producers

Despite the establishment of high-tech multinational enterprises (MNEs) in Ireland since the late 1950s, the country did not succeed in closing the technological gap with most of its EU counterparts. The weak National System of Innovation (NSI), and in particular low business and government R&D levels, combined with a lack of research and technology linkages between MNEs and indigenous firms, explain these poor results. However, the Shannon region in the West of the country presents some specific institutional characteristics that could theoretically make the region a strong technological enclave. The various actors in the region - i.e. the administrative, financial, political and research institutions, as well as the business organizations - have indeed infused a new type of economic development. After a brief review of the available concepts and models articulated around these actors and their interrelationships, the paper analyses whether the Shannon region, taken as an illustrative example, mirrors a specific economic and technological localized setting. The study is based on a survey of indigenous and foreign firms.