A Novel Magnetic Harmonic Gear

Magnetic gears offer several advantages compared to mechanical gears in terms of reduced maintenance, improved reliability, and inherent overload protection while having a high efficiency. This paper describes the principle of operation of a novel form of magnetic gear, which is particularly suited to applications for which a high gear ratio is required. The performance capability of such a magnetic gear is investigated, and it is shown that it transmits a ripple-free torque and that an active torque density of up to 150 $hbox{kN}cdot hbox{m/m}^{3}$ per stage can be achieved when high-energy permanent magnets are employed. Simulation results on this novel gear are verified by experimental measurements on a prototype.      

PM-assisted reluctance synchronous motor/generator (PM-RSM) for mild hybrid vehicles: electromagnetic design

This paper introduces the conceptual design and finite-element method analysis of a permanent-magnet-assisted reluctance synchronous motor/generator for mild hybrid vehicles where a large constant power speed range (6:1) is required and machine volume, converter peak kVA, and battery size are the main constraints. Careful flux-barrier and permanent-magnet sizing, high magnetic saturation, and current density are the main requirements for maximum torque production with constraint volume. A specific tangential force density of 4.33 N/cm/sup 2/ is obtained. Rated (continuous) power-battery limited is 2.5 kW at 42 V dc, from 1000 to 6000 r/min. The peak torque of 140 N/spl middot/m is obtained at 202 A (rms/phase) and can be secured up to 500 r/min. Peak power is still 7.85 kW at 6000 r/min at 42 V dc with an efficiency of 90%. Preliminary results on a prototype are also available.     

三种充磁方式轴向磁齿轮的磁场和转矩特性比较

依据永磁体充磁方向和排列方式的不同,轴向磁齿轮可分为轴向充磁磁齿轮、聚磁式轴向磁齿轮和Halbach式轴向磁齿轮。采用3D有限元法对三种轴向磁齿轮的磁场、转矩特性和轴向力进行了比较。基于气隙磁场的谐波分析,利用公式计算出各次谐波磁场产生的转矩和轴向力,得出各次谐波磁场对转矩传递和轴向力的作用。比较表明,聚磁式轴向磁齿轮的转矩能力和永磁体利用率最大,比轴向充磁磁齿轮提高了17.5%和32.6%,比Halbach式轴向磁齿轮提高了2%和15.1%。Halbach式轴向磁齿轮的气隙中引起转矩波动的磁场谐波的幅值最小,转矩波动也最小。轴向充磁磁齿轮低速转子的轴向力最小,比聚磁式轴向磁齿轮小38.3%,比Halbach式轴向磁齿轮小32.7%。     

磁场调制式磁力齿轮及其有限元计算

为避免机械齿轮振动,或要在分开物体间传递力矩,可以采用磁力齿轮传动装置。设计该磁力传动装置时需要对其设计参数进行精确计算。在电机设计时,使用有限元方法对一种大力矩磁力齿轮——磁场调制式磁力齿轮进行了磁场计算,为设计该磁力齿轮提供了有力的工具。     

阻尼绕组对磁力齿轮动态特性的改善

与传统机械齿轮相比,磁场调制式磁力齿轮输入与输出轴之间非机械连接,具有无磨损、无润滑、大速比与过载保护等特点,使得其在变速机械方面具有特殊应用价值。然而,由于两转子间存在非刚性磁耦合特性,导致在启动以及负载和速度发生变化时,出现暂态振荡现象。为了提高整个传动系统的动态稳定性,提出一种在高速转子侧增加阻尼绕组的结构设计,在电磁场有限元分析基础上,建立了动态仿真模型,对磁力齿轮增加阻尼绕组前后动态性能进行对比研究,结果证明阻尼绕组结构能有效减小传动系统的振荡幅值,缩短调节时间。     

新型永磁调磁式磁齿轮的设计与优化

为了提高磁齿轮的输出转矩和运行转速、减小永磁体的涡流损耗,提出一种新型永磁调磁式磁齿轮,分析其工作原理和转矩特性,结果表明相比较传统的磁齿轮,新型永磁调磁式磁齿轮具有传动效率高、转矩密度高、可高速传动的优点。在此基础上,为了获得新型磁齿轮的最优结构参数,以提升输出转矩和减小齿槽转矩为优化目标,提出一种基于参数敏感性和响应面法相结合的多目标优化方法,对新型磁齿轮的永磁调磁块、外转子及内转子永磁体等结构参数进行优化设计,利用有限元法分析优化前后新型磁齿轮的电磁性能,表明多目标优化方法可进一步提升新型磁齿轮的输出性能,为其应用和优化设计奠定了基础。     

双磁场调制磁齿轮转矩能力增强特性分析

磁齿轮能够实现低速大转矩输出。为了进一步提高同轴磁齿轮的输出能力,提出一种双磁场调制磁齿轮拓扑结构。双磁场调制磁齿轮将传统的表贴式同轴磁齿轮低速转子侧的转子轭用辅助调磁环代替,结构上包含2个转子,2个调磁环和3层气隙。分析双磁场调制磁齿轮的工作原理,采用有限元法,对新增调磁环的尺寸进行了优化。对比分析双磁场调制磁齿轮和传统表贴式同轴磁齿轮的磁场分布和传动转矩。不同传动比下,双磁场调制磁齿轮的转矩能力普遍高于传统表贴式同轴磁齿轮。当传动比为7.5时,双磁场调制磁齿轮的低速转子最大输出转矩达到70.81N·m,与相同尺寸的传统表贴式同轴磁齿轮相比,转矩能力提升了54%。稳定运行时,双磁场调制磁齿轮的低速转子转矩脉动有所增大。     

基于磁齿轮调制的复合电机有限元分析

为了降低机械损耗,获得高转矩密度电机,研究了一种磁齿轮复合电机,该电机充分利用磁场调制型磁齿轮内部空间,将磁场调制型磁齿轮和永磁电机复合在一起。利用有限元软件建立磁齿轮复合电机二维有限元模型,分析了电机磁力线分布、气隙磁密及对应的傅里叶分析、感应电动势、稳态运行转矩、齿槽转矩等特性。仿真结果表明,此类复合电机磁力线分布均匀,气隙磁密对应的最大谐波次数符合设计要求,三相反电动势对称性好,内外转子转矩比与传动比一致,齿槽转矩较小。与传统永磁电机相比此类电机有很好的转矩传输比和较高的转矩密度,具有很好的应用前景。     

高转矩密度磁力齿轮的拓扑结构设计与性能比较

永磁行星齿轮和同轴永磁齿轮是两类具有不同拓扑结构和运行原理的磁力齿轮,采用定量设计比较法设计了具有相同有效体积和永磁体用量的上述两类磁齿轮,并通过有限元分析法对二者的转矩传递性能进行比较研究。研究结果表明,永磁行星齿轮较同轴永磁齿轮有更高的转矩密度和更低的转矩脉动。此外,由于永磁行星齿轮具有更加灵活的运行模式,并且能实现功率分流,使其在混合动力汽车领域有很好的应用前景。加工了一台永磁行星齿轮样机,并搭建试验平台进行了相关的试验,结果表明了该拓扑结构的有效性。     

高性能磁力齿轮传动扭矩与效率的数值计算

为了获得高性能磁力齿轮的传动扭矩和效率等性能参数,利用Maxwell 2D软件对其进行静态、动态有限元模拟计算。计算出内磁转子、外磁转子以及调磁极片的静态扭矩;定义内、外磁转子分别以对应的转速运行,得出其功率损耗,进而得到其扭矩损耗;定义了磁力齿轮的3种运行方式,根据静态扭矩以及扭矩损耗的结果,推算出各种运行方式下效率的计算公式并分析其变化规律。分析的结果可以为磁力齿轮的设计制作提供依据。     

Mechanical design considerations for conventionally laminated, high-speed, interior PM synchronous machine rotors

This paper discusses mechanical design considerations that are particular to conventionally (i.e., radially) laminated rotors of interior permanent-magnet synchronous machines. Focus is placed on applications where the radial forces due to high-speed operation are the major mechanically limiting design factor. Proper design of the lamination bridges, or ribs, at the rotor outer diameter is explained in terms of the both material considerations and electromagnetic performance impact. The tradeoff of complexity versus performance associated with using strengthening ribs in the magnet cavities is discussed. The sensitivity of the mechanical design limitations to the rotor-shaft mounting mechanism is also highlighted. These effects are then analyzed using finite-element analysis for a 150-N/spl middot/m/6-kW integrated starter/alternator designed for operation up to 6000 r/min with an annular rotor to accommodate a torque converter or clutch assembly. This example demonstrates that it is possible to significantly improve the rotor's structural integrity using the techniques described in this paper with only a very modest impact on the projected machine drive cost.     

电动车用外转子永磁无刷直流电动机的研究

本文介绍电动车用高效外转子钕铁硼永磁无刷直流电动机。电机直接装于车轮产生转矩，取消差动齿轮和变速器，减小功消耗和提高效率。通过电磁场理论分析，也介绍了减小力矩波动的方法和无刷电机弱磁控制概念。     

钢球磨煤机系统的轴承故障诊断与分析

几个电厂的多台钢球磨煤机减速机或电机经常发生轴承损坏故障,通过对发生异常的磨煤机系统的振动情况进行现场测试,发现主要的振动频率为磨煤机小牙轮与大齿轮的啮合频率;另外,经常发生损坏的轴承其滚动体故障频率与该频率也比较接近或重合,说明造成齿轮啮合频率与滚动轴承故障频率相重合会降低滚动轴承的使用寿命.     

同轴式磁力齿轮试验样机的参数优化与设计改进

针对一台传动比为-15/7的同轴式磁力齿轮试验样机存在转矩密度偏低的问题,运用二维有限元法分析调磁极片的径向齿高、相对齿宽、连接桥位置及内外磁体充磁方式、磁体体积对转矩密度的影响,从而来寻找提升转矩密度的措施。结果表明,在不增加制造成本的前提下,通过改进调磁极片和磁体的相关参数使转矩密度提升43%,磁力齿轮外径缩小7.5mm。     

Optimal Design of Permanent Magnet Motor with Magnetic Gear and Prototype Verification

We designed a miniaturized permanent magnet synchronous motor with a magnetic gear by using an optimal design technique based on thermomagnetic field coupling analysis. To construct an even smaller motor, investigating the heat dissipation from the motor and increasing its rotation speed are necessary. We manufactured and tested the designed motor with a magnetic gear. The measured torque and motor efficiency demonstrated the high precision of the proposed design.     

Design consideration and performance of high-power and high-brightness InGaAs-InGaAsP-AlGaAs quantum-well diode lasers (/spl lambda/=0.98 /spl mu/m)

We conduct a theoretical analysis of the design, fabrication, and performance measurement of high-power and high-brightness strained quantum-well lasers emitting at 0.98 /spl mu/m. The material system of interest consists of an Al-free InGaAs-InGaAsP active region and AlGaAs cladding layers. Some key parameters of the laser structure are theoretically analyzed, and their effects on the laser performance are discussed. The laser material is grown by metal-organic chemical vapor deposition and demonstrates high quality with low-threshold current density, high internal quantum efficiency, and extremely low internal loss. High-performance broad-area multimode and ridge-waveguide single-mode laser devices are fabricated. For 100-/spl mu/m-wide stripe lasers having a cavity length of 800 /spl mu/m, a high slope efficiency of 1.08 W-A, a low vertical beam divergence of 34/spl deg/, a high output power of over 4.45 W, and a very high characteristic temperature coefficient of 250 K were achieved. Lifetime tests performed at 1.2-1.3 W (12-13 mW//spl mu/m) demonstrates reliable performance. For 4-/spl mu/m-wide ridge waveguide single-mode laser devices, a maximum output power of 394 mW and fundamental mode power up to 200 mW with slope efficiency of 0.91 mW//spl mu/m are obtained.     

传统充磁与正弦充磁磁齿轮磁场分布及转矩特性对比分析

为提高磁场调制式磁齿轮的转矩密度,改变传统充磁方式,分析了一种正弦充磁磁齿轮。利用Ansoft软件构建了两种充磁方式磁齿轮的有限元模型,在静态模型下分析了两种磁齿轮的磁力线分布,计算了内外层气隙磁通密度,获得了内外层气隙磁密的各主要谐波;计算了模型中内外转子的静态转矩和稳态运行转矩。对两种充磁方式磁齿轮的气隙磁密、谐波以及转矩进行了比较,结果表明在同体积下正弦充磁磁齿轮具有较小的谐波含量和较高的转矩。     

磁齿轮电机与集中绕组永磁电机的比较分析

当前低速大转矩传动系统存在机械振动、刚性摩擦等问题,根据调制型磁齿轮效应,磁场调制型永磁齿轮电机(FPGM)可用于低速大转矩直驱。通过分析FPGM与分数槽集中绕组永磁同步电机(FSCW-PMSM)的绕组磁动势各次谐波在电机中的作用,定性比较两者的异同。通过建立FPGM和FSCW-PMSM的有限元模型,分析了两者转矩特性、功率因数和参数特性的区别,验证了FPGM产生大转矩的能力,并为关键参数的分析设计提供了参考。搭建FPGM样机空载试验平台,并将试验数据与有限元分析结果进行对比,证明以FPGM提供低速大转矩方案的可行性。     

永磁齿轮在人工心脏中的应用研究

采用永磁齿轮作为人工心脏驱动方式是一种新设想。在计算永磁齿轮矩角特性基础上,研究了气隙对传递最大转矩的影响,并探讨了永磁齿轮理想转动状况。建立了人工心脏模拟实验装置,实验验证了永磁齿轮在人工心脏设计中的适用性。     

Influence of Magnetic Saturation on Sensorless Control for Interior Permanent-Magnet Synchronous Motors With Concentrated Windings

The influence of permanent-magnetic flux variation and magnetic saturation on sensorless control for interior permanent-magnet synchronous motors with concentrated windings is evaluated. By using finite-element method analysis, partial differential values of flux linkage are calculated directly and precisely in a short time. High-speed analysis of a motor voltage equation is realized by interpolating table data of calculated partial differential values. Analyzed results show good correlation with experimental results. The performance of sensorless control is greatly improved using analyzed results, and the influence of permanent-magnetic flux variation is predicted well. The proposed method is very useful for designing control algorithms, considering the influence of permanent-magnetic flux variation and magnetic saturation.