专利快讯

<正>专利名称::一种整距绕组开关磁阻电机专利申请号:CN201310416639.3公开号:CN103532264A申请日:2013.09.12公开日:2014.01.22申请人:东南大学本发明公开了一种整距绕组开关磁阻电机,该电机为双凸极结构,定子和转子上均设有凸极齿,但定转子上凸极齿的个数不相等。定子齿上绕有分布式整距绕组线圈,形成多相对称整距绕组结构,线圈为单层圈边,即每个定子槽只放     

转子甲类波绕组排列方法的探讨

为方便绕线型异步电动机的设计和接线操作,明确转子波绕组一端接线法十分必要。从电角度的观点出发确定三相绕组首端引出线位置。根据波绕组的连接规律进行各相带的槽号分配,进而利用Excel公式法编排绕组表。这种方法不但易于掌握,而且通过绕组表可直观的确定上下层整距、短距、引线线圈所在槽号,为绘制转子接线图和设计转子线圈奠定了基础。     

整距绕组分块转子开关磁阻电机的电磁设计

整距绕组分块转子开关磁阻电机具有高速运行时低风（油）阻和低铁心损耗等优点,特别适合用于航天航空驱动系统。根据整距绕组分块转子开关磁阻电机的基本工作原理,结合输出功率与平均转矩的关系,将绕组电流等效为方波,推导出了整距绕组分块转子开关磁阻电机的主体尺寸计算公式;基于电机定转子未对齐位置和对齐位置的电磁特性,以及整距绕组分块转子开关磁阻电机的电磁特点,确定了定、转子极弧系数选取的规则;同时分析了绕组匝数等主要尺寸的选取的规则;最后,基于上述方法优化设计了一台实验样机,并通过有限元仿真及实验验证了整距绕组分块转子开关磁阻电机的电磁设计方法的正确性。     

700kW船用轴带无刷双馈发电机的设计与测试

无刷双馈发电机转子绕组谐波含量大,导致发电机损耗大、效率低,制约了其工业应用。为解决此问题,运用绕组齿谐波原理和正弦绕组理论,提出一种采用多节距不等匝多层线圈设计转子绕组的无刷双馈发电机,并结合设计实例进行了详细分析。这种新结构能有效提高转子绕组的导体利用率,并减少除了两种主要极对数之外的其他谐波含量。通过有限元建模仿真和样机实验验证了结构设计的正确性。样机实验结果表明,所提出的多节距不等匝多层线圈转子结构的无刷双馈发电机具有良好的性能指标。     

鼠笼型异步电动机转子导条型式的选择

0引言 异步电动机主要由定子和转子组成,转子是旋转部件,转子绕组型式有两种：其一是将线圈下线到转子槽内称为绕线转子,其二是转子槽内是铝或铜条及端环组成的短路绕组称为鼠笼型转子。本文讨论的是鼠笼型转子结构与导条型式的选择。导条型式分为两大类：即铸铝转子（将铝铸在转子槽内,并与端环铸成一体,形成短路绕组）和铜条转子（将铜导条下到转子槽内与铜端环焊成整体,形成短路绕组）。由于导条型式的不同,决定了转子结构的不同,对电动机的性能影响也不同,所以应该按使用要求和设计需要合理地选择。     

二倍极绕线转子异步电动机转子绕组的方案选择

绕线转子异步电动机的变极调速,其可行性决定于能否得到较为简单的转子绕组的变极方案。这需视具体的变极比而定,现对较常用的二倍极比的转子绕组变极方案提出几种方案供参考。一、三相三集电环方案首先,选定线圈节距使能适应高、低速运行的需要,一般可选对低速运行接近满节距的线圈;其次使用对高速运行时为单一120°电角度相带分布的绕组。这样在低速     

显极式电机转子接地查找

显极式转子绕组,其接地故障时有发生,严重时会危及电机的安全运行,所以要及时查出接地线圈。 传统方法是对半断开法,费事麻烦。我们采用直流压降法则很简单,一台24极1250kW大电机转子,不要10min便可准确地查出接地线圈。 原理:在转子绕组上加直流电压,因每个线圈的直流电阻相等,所以其压降也相等。良好的绕组对地不成通路,线圈对地无电压降。当有的线圈接地时,该线圈对地(轴)电位相等,其余线圈对地电位会因距     

直流发电机增容改造技术

阐述了某重型机械厂真空超速室发电机增容改造技术。主要介绍了电磁设计中斜槽铁心、变断面电枢绕组的选用、每槽2片全节距异槽式单迭绕组的优点等;结构设计中转子支架轴结构、电枢迭片铁心特点、主换向极铁心及线圈结构特点等。简单介绍了换向器结构、刷杆座圈结构以及VPI绝缘工艺。     

基于电流补偿策略的转矩分配函数法抑制整距绕组分块转子SRM的转矩脉动

整距绕组分块转子开关磁阻电机具有单位铜耗下输出转矩大、损耗低等优点,但转矩脉动大。本文采用余弦TSF控制法即通过控制电机各相电流产生的转矩分量使得低速时整距绕组分块转子开关磁阻电机的输出转矩脉动降低。针对电机转速升高后,由于实际相电流不能跟踪参考相电流,以及关断区间的电流不可控导致电机转矩脉动增大的问题,提出增大或减小其他相的相电流进行补偿的转矩控制策略并进行了分析。仿真和实验结果表明,该电流补偿策略的转矩分配控制法可有效抑制整距绕组分块转子开关磁阻电机的转矩脉动。     

电力发明专利信息

中华人民共和国专利局 2 0 0 1年 4～ 6月授权的电力发明专利共约 30余项 ,现将其中部分项目介绍如下。采用去环流技术的交流电机转子绕组及其联结方法(ＺＬ 9411744 5 .Ｘ)本发明为采用去环流技术的交流电机转子绕组及联结方式 ,每个绕组线圈均有匝数不等的两个子线圈 ,沿转子圆周为ａ的两个绕组线圈按多匝子线圈与另一少匝子线圈相串联成一条支路 ;少匝子线圈与另一多匝子线圈相串联成另一条支路 ,然后并联连成一个线圈对 ;相绕组以线圈对为基本单元并或串联构成。本发明所述的电机转子绕组适合用于远极比的绕线型变极电动机 ,可满足超重…     

Application of a force‐balanced coil to a tokamak device

High field is very favorable for magnetically confined fusion devices such as a tokamak, but electromagnetic force derived from the field becomes a fatal problem. In particular, the largest in‐plane centering force hinders toroidal field coils from operating at higher fields. Variable pitch multihelical coils, which we term force‐balanced coils (FBCs), by which this force is drastically reduced, are proposed for the coil system of tokamaks. FBCs can also provide poloidal flux swing for plasma breakdown and current induction during the ramp‐up phase of the coil current. In this paper, we indicate how to design FBCs for tokamaks. The fusion reactor‐size FBCs are designed and compared with that of the conventional toroidal field coil system. © 1999 Scripta Technica, Electr Eng Jpn, 130(3): 39–48, 2000     

Experiments on a tokamak device with force‐balanced coils

High field is very favorable for magnetically confined fusion devices such as a tokamak, but the electromagnetic force derived from the field becomes a fatal problem. In particular, the largest in‐plane centering force hinders toroidal field coils from operating at higher fields. Although variable‐pitch multihelical coils, which we term force‐balanced coils (FBCs), by which this force is drastically reduced, were proposed for the coil system of tokamaks, there had been no actual tokamak device with FBCs. Therefore, Todoroki‐1, a small tokamak device with FBCs has been manufactured and experiments started. In this paper, the structure of Todoroki‐1 is indicated, and the stray magnetic field and centering force on FBCs are investigated. The plasmas have been generated in the device, and attempts at better plasmas are beginning. © 1999 Scripta Technica, Electr Eng Jpn, 130(3): 19–29, 2000     

The effect of surge testing on the voltage endurance life of stator coils

Surge tests with short rise times are used to ensure turn insulation integrity in form-wound vacuum-pressure impregnated (VPI) coils prior to resin treatment. Use of this test migrated from the evaluation of fully processed generator bars and random wound stators. The dielectric properties of the insulation in these systems are fully developed at the time of testing. This is not true of "green" (unimpregnated) VPI coils. Although surge testing is a valuable manufacturing quality test, an excessive transient electric field in uncured coils may cause irreversible changes to the insulation. These changes may affect the life of the insulation system after complete impregnation and cure. This paper describes laboratory tests and finite element simulations that examine the effect of applied surge test voltage and number of applied pulses on voltage endurance (VE) life. The sympathetic voltage response in a single coil as a function of its location within a winding is described for a stator undergoing green surge testing as part of a quality assurance program. Results of VE testing and sample dissection data are presented. Test voltage was identified a more significant factor on VE life than the number of pulses applied.     

Scaling Law of Coupling Coefficient and Coil Size in Wireless Power Transfer Design via Magnetic Coupling

Wireless Power Transfer (WPT), such as magnetic resonant coupling using a magnetic field, is being studied and discussed for a wide variety of applications. When the transmission distances are large, very large transmitters and receivers need to be considered. However, in the early stages of an investigation, it might be prohibitive to manufacture and evaluate coils of such a large size. To reduce costs and effort, a scaling law can be used to estimate the WPT efficiency of very large coils using the results of smaller coils. In this paper, a scaling law is proposed that relates the coil size to the coupling coefficient, assuming the ratio between the coil diameter and coil length remains constant. The coupling coefficient is one of the parameters that determine the maximum efficiency of magnetic field WPT. The proposed method was verified by an electromagnetic field simulator and experiment. The results of this study provide an easy method for estimating the WPT efficiency of very large coils.     

具有短距效果的单层绕组交流电机的特性改善

本文介绍了中小型三相交流异步电动机具有双层短距效果的单层绕组的构成、绕组系数、等效电路,并做实验比较了两种绕组的谐波转矩和电势的大小.证明了单层短距绕组异步电动机的性能得到了明显的改善.     

磁谐振无线电能传输系统线圈设计综述

线圈是无线输电系统中实现电磁耦合谐振的核心部件,具有高品质因数和均匀磁场的线圈是无线电能传输系统获得高传输效率和稳定输出的重要保证。基于磁谐振无线电能传输系统的基本结构和工作原理,总结了磁谐振无线输电系统中线圈的主要设计方法。首先介绍了常用的线圈类型和线圈尺寸的优化选择;然后对比了不同的线圈电感计算公式的适用范围;最后论述了线圈内阻、匝间距等参数对磁谐振无线输电系统传输效率和输出功率的影响。此工作对磁谐振无线电能传输系统的线圈优化设计有一定的指导意义。     

水轮发电机水内冷定子温度场的分析方法

本文利用三ＣＡＤ软件建立刘家峡和三峡水内冷定子三维几何模型，通过接口程序直接输入到有限元分析软件中，计算了一个齿距内，包括上下端部线圈的轴向定子整体三维温度场，在三维温度场分析领域一条新途径。刘家峡电站实测数据表明，本方法具有较高的准确性和实用性。     

电力变压器的动稳定

在变压器短路电动力的计算中,目前是以静态力代替动态力的方法来进行的。这不能适应变压器机械强度的要求。针对此问题,从电动力的基本理论出发,建立起变压器的动态数学模型,对变压器在短路电流作用下线圈产生的动态力进行了理论分析和计算,对在短路电流作用下的变压器线圈(器身)绝缘结构进行了初步研究,提出了动稳定的计算方法。     

Pitch control based on voltage dip detection for improving the LVRT of wind farm

For the stability of power systems including large‐scale generation of wind power, wind farms are expected to fulfill the requirement with the capability to remain connected to the systems during a momentary voltage dip occurring in power networks. This has prompted many utilities to adopt the low‐voltage ride‐through (LVRT) of wind turbine generators (WTGs) as one of the requirements in interconnection of large wind farms. This paper presents a new method of pitch angle control for fixed‐speed wind turbine (FSWT) to achieve LVRT capability improvement. The FSWT is equipped with directly grid‐coupled squirrel‐cage induction generator and the LVRT behavior of such wind turbine is closely related to the overspeeding of wind turbine rotor during voltage dip. If the turbine rotor speed can be reduced quickly during voltage dip so as not to rise over the maximum speed, then the sudden disconnection of WTG can be avoided. The proposed pitch control system can modify the pitch angle in the short response time by the coordination of protective relay. Then the pitch angle is adjusted by a feedback proportional integral controller based on the measurement of induction generator terminal voltage. Simulation study shows that the application of the proposed pitch control system can improve the LVRT performance of a wind farm equipped with FSWTs. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

主变平衡绕组故障引起差动保护动作的分析

主变平衡绕组的引出桩头发生两相短路导致主变差动保护动作,从波形上看故障切除过程中平衡绕的桩头由两相短路发展为三相短路.简单介绍了主变平衡绕组的作用、详细介绍现场故障检查以及对差动保护动作波形的分析,还从理论角度分析了YO/△-11联结组别的主变三角形侧两相短路时星形侧三相绕组上流过的故障电流的幅值及角度,其分析结果和实...