Modern electric insulating materials for the insulation systems of rotating electric machines

Modern insulation systems of turbo- and hydrogenerators, large electric machines, and traction motors based on new electric insulating materials (EIMs) produced by the JSC Elinar Holding Company (Elinar HC) are described briefly. The technical characteristics of some new EIMs are given.     

Computer modeling for enhancing instruction of electric machinery

This paper discusses the use of computers for modeling of electric machinery at the undergraduate level to enhance the lecture as well as the laboratory part of a course on electric machinery with introduction to power systems. It explains how computer simulation helps students not only get a better understanding of the advantages and limitations of computer simulation, but also get a better feel for the physical concepts they study in the lecture and laboratory part of the course. Sample computational projects assigned to the students are described and simulation results obtained from the computer models are presented     

Computer aided instruction of power transformer design in theundergraduate power engineering class

This paper describes a single-phase transformer design suitable for classroom use. The scope of this design is limited to the specification for the core and coils of the transformer. Both shell and core configured transformers are designed in this paper. A computer program is developed for the purpose of illustrating the design procedure and demonstrating how it works. The objective is to meet all performance requirements at minimum cost     

Computer graphics

The history of computer graphics is sketched. Hardware principles are outlined, and the various types of display are described. Computer graphic standards are discussed. Future developments are predicted     

New electric insulating materials for the insulation systems of rotating electrical machines

A wide range of nomenclature and properties for new materials for the insulation of high voltage electrical machines and traction motors of F and H insulation classes developed at Elinar Holding Company are presented in the report.     

GB 50170-2006《电气装置安装工程旋转电机施工及验收规范》修订说明

1 概况 本规范是根据建设部《关于印发〈二○○一～二○○二年度工程建设国家规范制定、修订计划〉的通知》(建标[2002]85号)的要求,由中国电力企业联合会负责,国电电力建设研究所会同有关单位,在《电气装置安装工程旋转电机施工及验收规范》GB50170-1992的基础上修订的.该规范由1993年7月1日发布实施,至今已有十多年了,规范中所规定的不少条款,已与当前实际有较大的出入,因此,需要对本规范进行修订.     

基于SVG的电力系统图形互操作研究

可缩放矢量图形(SVG)作为IEC61970标准推荐采用的公共图形交换的文件格式.提出要实现不同开发商开发的图形文件信息的相互识别和交换,以及实现电力系统图形的互操作的关键是要建立基于SVG格式所组成的电力系统图形文件各元素的语义表达格式标准和电力系统图形文件的组成结构标准,并按照IEC61970描述电力系统资源的标准...     

Computer aided power transmission planning

The Interactive Power Transmission Planning (IPTP) package developed at the Kuwait Institute for Scientific Research comprises a security assessment program so the network planning engineer can test the technical feasibility of a given network and a sensitivity analysis program that indicates to the planner the best line to reinforce. These basic computational planning facilities are presented to the engineer through special software using interactive computing and computer graphics. The package is devised so that it can be used by engineers with limited computer programming and numerical analysis skills.     

A discharge locating probe for rotating machines

The basic principles of an improved Tennessee Valley Authority (TVA) probe known as the discharge locating (DL) probe are presented. The principal features of the new device are very-high-frequency detection using a capacitive sensor and microprocessor-based signal processing. These features are intended to make the probe easier to use and less ambiguous in the interpretation of results. The coupling technique used permits significantly improved spatial resolution of the discharge source and immunity to radiated electrical interference. Details of the signal processing electronics and field experience are described     

图形辅助智能开票专家系统的设计与实现

针对现有操作票自动生成系统通用性和出票正确性水平仍需提高的现状,提出一种图形辅助智能开票专家系统.对整个系统功能结构作了阐述,具体对图元类的设计、图形辅助智能开票、图库一体化的数据库设计做了进一步的改进.系统结合专家系统的正向推理控制策略,保证了开票的合理性和正确性;利用面向对象技术改善了传统图形系统设计中图形编辑模块的可扩展性和通用性;图库一体化更使得系统的操作、维护简单方便.     

图形辅助智能开票专家系统的设计与实现

针对现有操作票自动生成系统通用性和出票正确性水平仍需提高的现状,提出一种图形辅助智能开票专家系统。对整个系统功能结构作了阐述,具体对图元类的设计、图形辅助智能开票、图库一体化的数据库设计做了进一步的改进。系统结合专家系统的正向推理控制策略,保证了开票的合理性和正确性;利用面向对象技术改善了传统图形系统设计中图形编辑模块的可扩展性和通用性;图库一体化更使得系统的操作、维护简单方便。     

Thermolite electric-insulating system for electric machines

A Thermolite electric insulating system of heat-resistance classes H and C is tested and the test results are presented. It is shown that the developed insulating system makes it possible to increase the motor’s power compared to traditional systems.     

Modelling of induction machines for electric drives

The author presents several linear and nonlinear models suitable for transient and steady-state analyses of induction machine drives. The models are presented in equivalent circuit form to preserve the identity of nonlinear parameters. The circuits, designated as Γ or inverse Γ form, are simpler than the conventional T-form circuit. Their parameters are readily determined from terminal measurements. The major effects of magnetic nonlinearity are included in the models in a way that is more accurate than that usually obtained with the conventional T-form circuits. Modeling of time harmonics is also discussed     

温差电致冷组件计算机辅助设计

在温差电组件设计过程中,可变参数较多,得到的组件结构有多种,靠人工计算分析工作量较大;同样,对应多级组件,计算量更大,容易出错,设计得到的最终结果可比性较差,得到最佳设计方案的几率较小。采用计算机辅助设计解决以上问题。用VisualBasic语言编写了设计程序,该程序有良好的输入界面,使用者清晰地了解操作过程,一步一步完成其设计。在设计过程中,该程序提供所有设计的可能性,设计人可随意改变设计参数,得到任意结果,通过比较得到最优设计结果。该程序能够进行从单级组件到二级组件的设计,设计输出为表格形式,设计结果可保存再用。     

江门市电网规划计算机辅助系统

介绍了江门市供电局计算机辅助电网规划系统,具体地阐述了该系统的总体结构及主要功能。该系统充分地利用现有配电网地理信息系统,实现电力资源的合理调配,并成为江门供电局电网规划的新型工作平台。     

配电网规划计算机辅助决策系统

给出了配电网优化决策的数学模型,并开发了图形化的配电网规划计算机辅助决策实验系统.配电所的初始位置通过负荷矩法确定后,采用自动寻优算法确定其最终位置坐标;采用prim算法来优化网架结构;利用经济电流密度法选择导线截面,并采用边际电压费用法加以校验.实验系统以AutoCAD为图形界面,结合数据库系统,实现了数据与图形的联动,方便数据输入和结果查看.     

Trends in insulation materials and processes for rotating machines

Market pressure for cost reduction and more rapid innovation has taken away the privilege for the insulation design engineers to re-test everything according to time-honored “in-house” methods     

Unusual PD pulse phase distributions in operating rotating machines

The position of partial discharges (PD) with respect to power frequency phase position has long been known to provide useful information on the nature of deterioration of electrical insulation. In the past, virtually all such data has been from PD tests performed in the laboratory on static models or equipment. Improvements in the past 15 years in noise elimination technology have made it possible to monitor the PD activity (number, magnitude and phase position) in the HV stator windings of operating motors and generators. Over a two year period, the PD activity was recorded on more than 100 motors, hydrogenerators and turbine generators, and the pulses analyzed with respect to the ac phase position, with a resolution of 3.6°. In the majority of stator windings, the PD pulses occurred in the expected portion of the ac phase, i.e. Between 0 and 90° as well as between 180 and 270°. However a significant number of instances were recorded where the pulses appeared to be shifted ~30°. This is probably due to the phase-to-phase electric stress which occurs in the endwinding portion of a three phase stator winding. In many other machines, the PO phase positions were very different from the expected patterns determined from static tests. In some of these cases, such results were obtained on machines with suspected loose stator windings. It seems reasonable to conclude that the unusual PD patterns may be due to the influence of moving stator coils on the PD patterns. Such an influence is not easy to simulate in static laboratory tests. PD pulse phase analysis is shown to be a useful means of helping to determine the main deterioration mechanisms of stator insulation systems of operating motors and generators