晶闸管的分力顶压机构设计

介绍了一种晶闸管的分力顶压机构、应用这种顶压机构能充分满足晶闸管的安装要求，并能减小对顶压系统的强度要求，最大限度地减小顶压拧紧力矩，便于安装和维修，符合人机工程学要求。     

不用互锁控制线实现远距离双电源互锁互投

介绍一种远距离双电源互送电的控制电路，该电路不用互锁控制线实现互锁，避免误操作，减小线损和停电损失。     

低介电常数新型绝缘纸板及其在变压器绝缘上的应用

为使油隙与纸板的介电常数接近以减小变压器的绝缘尺寸，开发研制了低介电常数的新型纸板，本文介绍了这种新型纸板的一些性能。在变压器绝缘设计中应用这种纸板可实现减轻重量和减小尺寸的效果。     

电网谐波分析及其对策

介绍电力网谐波的产生机理及产生谐波的谐波发源地，特别指出谐波对电力系统所产生的危害，提出减小谐波影响的技术措施和管理措施。     

系统工作票的研究与应用

介绍了一种机组大小修使用的系统工作票的模式、特点和使用情况。与常规工作票相比，可以大大减小工作票的数量，提高工作票的管理水平。     

一种新型不连续导电模式下的单级交错PFC

本文提出了一种新型交错单级功率因数校正电路(PFC)。为了实现功率因数校正和减小电感体积，boost电感工作在不连续导电模式。此单级PFC电路采用两个boost电路交错运行，减小了输入EMI滤波器的尺寸和开关电流应力，同时也减少了输出纹波。在介绍电路工作原理的基础上，对其输入电流进行了分析，给出了仿真与实验结果。     

提高永磁电机性能的新途径：力矩波动的减小

介绍永磁电机设计技术，通过斜磁钢及合理选择磁极弧度等来减小力矩波动。     

回转式空气预热器密封间隙控制系统改造

介绍了回转式空气预热器密封间隙控制系统的技改过程和方法。采用工控机与可编程逻辑控制器（PLC）组成控制系统，增加过电流调节和保护等策略和功能，提高了系统可控性，减小了空气预热器漏风率。     

交流测速发电机轴误差电压的测量方法

交流测速发电机零速输出电压的存在将对系统工作带来不利的的影响，为减小其影响，需对零速输出电压有所了解，以便生产厂家能在生产过程中加以控制和测量，使其能在系统中加以补偿，以减小或消除其影响。零速输出电压可分为基波同相分量、基波正交分量、轴误差电压、位置误差电压等。文中介绍轴误差电压的概念和测量方法。     

提高RP型中速磨出力和石子煤的排放

介绍了对Ｒｐ型中速磨的试验研究，找到了影响磨煤机出力和石子煤排放的主要原因，提出了减小磨煤机进口通风面积，修改风煤比等改进措施     

定子槽口系数对永磁无刷直流电动机转矩波动的影响

转矩波动是永磁无刷直流电动机产生振动和噪声的主要原因。引起永磁无刷直流电动机转矩波动的原因主要有齿槽效应转矩、电动势波形的缺陷及换相转矩波动等。主要分析了槽口系数对转矩波动的影响,以永磁无刷直流电动机为例,利用有限元分析了整数槽和分数槽电机定子槽口系数变化对齿槽转矩的影响及槽口系数变化对气隙磁密及谐波的影响;最后计算改变槽口系数对电机主要性能的影响。     

Temperature effects on torque production and efficiency of PMmotors using NdFeB magnets

Recent developments in high energy magnets have created widespread interest in the area of permanent magnet (PM) motors. The use of PM synchronous motors or brushless motors to replace conventional DC or induction type motors has not been as speedy as anticipated earlier. This paper deals with the temperature effects of PM motors using neodymium magnets on the torque production capability and on the efficiency of the motor. When PM motors are designed to operate in a wide temperature range, the reversible demagnetization of the neodymium magnets with temperature and the increase in winding resistance with temperature influence the maximum torque capability at rated speed and efficiency of the PM motor. The maximum torque at rated speed is limited due to the fixed DC link voltage of the inverter feeding the motor. In this paper, it is shown that over an operating range of -40°C to 150°C the maximum torque capability and efficiency of the motor can vary over a wide range. It is also shown that for certain designs, a near flat maximum torque versus temperature characteristic may be obtained. The major factors influencing these variations are identified. The discussion in this paper is concentrated on PM motors with a trapezoidal back EMF waveform. The idea could be extended to sinusoidal back EMF motors and to PM DC motors     

Halbach永磁阵列无刷直流电机转矩的解析计算和分析

Halbach永磁阵列具有灵活配置电机气隙磁通密度、磁屏蔽的特点,将其用于无刷直流电机以增加电磁转矩、降低齿槽转矩。在保角变换求解电磁场基础上,给出无刷直流电机电磁转矩与齿槽转矩的解析计算模型,通过有限元仿真对该模型的准确性进行证明;使用该模型分析每极两块(1P2p)、每极三块(1P3p)Halbach永磁阵列中主磁钢弧角和辅磁钢充磁方向角对无刷直流电机电磁转矩与齿槽转矩的影响,对比分析径向充磁、平行充磁和Halbach永磁阵列的无刷直流电机电磁转矩与齿槽转矩随永磁体厚度的变化规律。分析结果表明,合理配置无刷直流电机Halbach永磁阵列中主磁钢弧角和辅磁钢充磁方向角可提高电磁转矩、降低齿槽转矩,当永磁体厚度增加时,Halbach永磁阵列更有利于电磁转矩增加。     

A novel polyphase multipole square-wave permanent magnet motordrive for electric vehicles

A novel high-power-density permanent magnet (PM) motor drive for electric vehicles (EVs) is proposed. The motor is a polyphase multipole square-wave PM motor, which can be classified as a kind of PM brushless DC motor. The distinct features of the proposed motor as compared to those of the conventional PM brushless DC motor are as follows. First, the multipole magnetic circuit arrangement enables the minimization of the magnetic yoke, resulting in the reduction of motor volume and weight. Second, the coil span is purposely designed to be equal to one slot pitch, thus saving the amount of copper used. Third, by using a fractional number of slots per pole per phase, the arrangement of the numbers of poles and slots is so unique that the magnetic force between the stator and the rotor at any rotating position is uniform, hence eliminating the cogging torque that usually occurs in PM motors. Finally, the motor can be controlled to operate at a constant torque region and a constant power region with field weakening, thus both high starting torque and high cruising speed can be achieved. Therefore, as the proposed motor drive possesses the distinct advantages of high power density, high efficiency, and superior dynamic performance, it is very suitable for EV applications. A prototype of a five-phase 22-pole 5 kW motor drive has been designed for an experimental EV     

永磁无刷直流电机负载磁场及其电磁转矩的计算

该文在考虑齿槽影响的前提下，建立了永磁无刷电机电枢反应磁场的解析计算模型，求出永磁电机相绕组的自感和互感。在对水磁无刷直流电机空载气隙磁场和空载相绕组反电动势求解的基础上，结合永磁无刷直流电机主电路的拓扑结构，构造出电机绕组的场路耦合模型，由此计算出电机相绕组电流变化波形。在考虑齿槽影响情况下，计算出永磁电机在任意时刻的电枢反应磁场和负载气隙磁场，进而计算出永磁无刷直流电机产生的瞬时电磁转矩，以便定量分析永磁无刷电机的电磁转短被动和绕组换相引起的转矩被动，为分析永磁无刷直流电机的工作特性和振动噪声提供了可靠的依据。     

电动汽车用永磁无刷直流电动机瞬态磁场分析

针对一种电动汽车轮毂直接驱动用外转子永磁无刷直流电动机,应用"场一路"耦合和运动边界法,进行了瞬态磁场分析,对动态特性进行模拟,准确计算出起动过程中的电流、转矩和转速。     

新型盘式无刷直流电动机及其控制器的设计

盘式无刷直流电机低速下力矩大,在电动机辆中能够直接驱动前轮或后轮,从而省去了机械变速装置,不仅减轻了整车重量,而且还提高了系统效率。文章介绍一种新颖的盘式电机绕组结构及其计算方法,论述了控制器中能量反馈功能的原理。实现这一功能在一定程度上延长了电池一次充电的使用时间,在电动车辆中具有特别的意义。     

永磁正弦无刷直流电动机力矩波动的测量

针对力矩波动问题 ,提出了平衡式直接测量和电流式间接测量的原理和实现方法 ,并进行了误差分析。对实际无刷直流电动机系统的波动力矩进行了测试 ,验证了测量方法的正确性     

大功率GTO等效传热模型的研究

研究发现GTO动态热阻变化率的对数具有分区间近似线性的规律,提出可采用分段拟合的方法初步获得GTO的高阶传热模型。基于最速下降原理构造了一种迭代算法,可以精确整定等效传热模型的各个参数,并研究了下降因子对迭代收敛性的影响。与GTO的实测动态热阻曲线比较,该模型的计算误差在±3%以内。将此传热模型集成在损耗分析软件中,可分析GTO的瞬态传热特性。     

Permanent magnet brushless drives

The purpose of this paper is to present an optimal efficiency control scheme for constant power operation of phase decoupling (PD) PM brushless DC motor drives. The key is to adaptively adjust the advanced conduction angle to minimize the system losses for a given operation point in the constant power region. The strategy for constant power operation of PD PM brushless DC motor drives is exemplified using a 5-phase 22-pole PD PM brushless DC motor. In the sections that follow, the newly-developed optimal efficiency control technique is then illustrated. Then, after describing the corresponding implementation, both computer simulation and experimental results are presented, and some conclusions are offered