汽车座椅电机的低频NVH性能分析与优化

对某型号汽车座椅气泵电机的低频(20～200 Hz)振动噪声来源进行分析,采用阶次分析方法确认主要频率对应电机的第一阶振动噪声。并针对转子动不平衡量和转子气隙偏心采用仿真分析和实验验证等方法,使电机低频段振动和噪声值降低至预定范围,满足设计要求。结果表明,对于转子动不平衡量,合理控制动不平衡量值,有利于低频振动和噪声值的降低。转子气隙偏心方面,随着气隙偏心距的增加,径向不平衡磁拉力也会越明显。较小的气隙偏心距对电机的低频振动噪声的改善有较大的帮助。该研究和验证结果可为类似电机的低频NVH性能改善提供有效的理论支撑和试验依据。     

315-2 132 kW电机通风噪声频谱的测量与对比

针对功率和转速相同的两台电机噪声线性值、C计权声压级（LpC）相差无几,但对电机噪声等级作评定的A计权声压级（LpA）相差很大的情况,对两台电机进行了噪声频谱对比试验,通过试验得出,该情况是由电机的通风噪声频谱不同引起的。介绍了简便实用的频谱估算方法,提出可以通过调整风扇的设计将通风噪声主要成份的频率由中频段向低频移动,从而有效改善电机的噪声等级。     

基于声阵列混合动力电动客车电机系统噪声测试研究

介绍了电动汽车电机驱动系统测试平台,基于传声器阵列及分析系统对混合动力电动客车电机系统在额定转速不同转矩的工况进行了噪声测试,试验结果表明在额定转速不同转矩时随着转矩增加其噪声幅度,在低频时相对减少,在中频时相对增加,而在高频时则相对不变。     

低地板有轨电车牵引电机试验噪声异常的处理分析

某型低地板有轨电车牵引电机在组合试验中出现噪声异常现象,经过对比该型电机单台试验与组合试验数据后,判断该异常噪声为电机固定工装所引起。为此,通过ANSYS有限元模态仿真计算,结合工装模态测试,分析了电机固定工装对牵引电机噪声的影响,并对原有固定工装进行了设计优化,解决了组合试验噪声异常的问题。     

积分式阶梯斩波限流步进电动机驱动电源

一、引言单电压大功率晶体管斩波限流步进电动机驱动电源虽有许多优点,但是在其驱动下,电机低频运行时振动和噪声较大,因而限制了步进电机的应用。本文介绍一种积分式阶梯斩波限流步进电动机驱动电源。它使步进电机在低频运行时,电机的振动和噪声有明显的改善,且其它特性没有降低。二、两种步进电机驱动电源的比较步进电机在低频运行时,采用单电压斩波限流步进电动机驱动电源和采用积分式阶梯斩波限流步进电机驱动电源电机绕组的电流波形,分别如图1、图2所示。     

小型电机波形弹簧片对振动的抑制作用

由于轴承存在游隙及其它原因,使电机运行时会产生振动及噪声。试验证实,这种轴向振动其频率较低(200Hz以下),大都在125Hz左右处有一与总量相近的峰值。噪声频谱也在这个频段有一明显峰值。见图1。当振动过大时125Hz的低频噪声有可能成为有影响的噪声源(A计权值)。 Y系列电机(H132及以下)在轴伸端     

空调用永磁无刷直流电机噪声研究

本研究针对永磁直流电机噪声大的问题,使用BK噪声和振动测试仪确定了低频噪声为电机换向噪声,高频噪声为径向电磁噪声,并从减振的角度提出了具有一定可行性的改善措施。     

起重冶金电机低频噪声分析

采用电磁噪声的一般分析方法，以8p电机采用60／48槽配合所产生低阶次力波分析为例，对绕线型起重冶金电机的电磁噪声进行了定性分析，并给出了控制典型规格低频噪声的措施。     

基于电机本体的新能源客车电磁噪声分析

为了研究新能源整车在行驶过程中的高频电磁噪声,采用试验与仿真相结合的方法,对某款新能源客车进行噪声、振动与声振粗糙度(NVH)测试,对新能源客车电机进行电磁仿真分析。对求解的电磁力密度进行时空的二维傅里叶变换,结合试验数据确定了电磁噪声主要来自于0阶72倍频;从电机本体出发,以电机转子的磁钢夹角、磁钢长宽等结构参数为设计变量,优化电机电磁力密度与转矩脉动;同时对优化后的模型利用有限元方法进行电磁、结构与声学的多物理场联合仿真,进一步求解电机的电磁噪声,并进行整车的NVH试验验证。试验结果表明:优化后的整车总体噪声减小了8.53 dB(A),电机72倍频噪声最大值减小了18.59 dB(A),减速机7阶噪声最大值减小了5.02 dB(A),仿真结果与试验测试结果吻合。     

变频谐波对电机振动噪声特性的影响规律

变频电机的振动噪声是影响电驱动产品应用的重要因素.为更准确掌握变频电机振动噪声激励,设计低噪声变频电机,该文建立变频电机振动噪声特性的一种分析模型,从变频机理出发,推导正弦脉宽调制(SPWM)变频器的输出谐波,再根据麦克斯韦定律计算分析变频激励下电机气隙的电磁激励力特性,并基于有限元法建立电磁-固-声多场耦合仿真计算模型,最后通过对比实测电机的声功率总结出变频谐波对变频电机振动噪声特性的影响.分析结果表明,电机振动噪声在低频部分的谐波由电机的调制频率产生,而变频器引入的高频谐波会使电机在开关频率附近辐射大量的噪声,因此,低噪声变频电机的设计必须消除或者削弱这些谐波.     

工业电机中的滚动轴承噪声

在工业电机出厂检验以及运行过程的机械故障中,轴承的噪声问题一直是困扰各界的重要问题。越来越多的专业人士开始关注如何降低轴承的噪声,如何判别轴承的非正常噪声,对电机中轴承的噪声问题也进行了深入地研究。从轴承的正常噪声机理入手,介绍影响轴承噪声的几个重要因素,同时提出了相应的解决方案。     

New PWM Method for Fully Digitized Inverters

The development of digital devices has led to the production of PWM inverters for driving induction motors having high-frequency carriers over 10 000 Hz. However, the popular digital devices exhibit difficulties in arriving at the precise switching instants because of limitation of available memory capacity and of bits, especially in the low-frequency region. Basic discussions on the magnetic flux and torque ripple and an introduction to a memory-saving and low-torque-ripple new PWM (split zero vector) method are given. The experiments show fairly good current waveforms, low iron loss, and low acoustic noise.     

浅析中型异步电动机噪声问题

通过对国产电机与西门子电机噪声的分析对比，从机械噪声，通风噪声，电磁噪声等三方面入手，论述了产生机电器声根源，并提出降低噪声的具体措施。     

Suppression control of speed variation in an induction motor with fluctuating load by repetitive learning control

Induction motors are robust and inexpensive machines and are used widely for variable speed control because of the recent development of electronic technique. In the case where loads of the motors are compressors, pumps, and so on, the constant V/F control of the induction motors usually is employed because it is difficult to install speed sensors and accurate speed control is not required. In such loads, the rotational speed of the motors fluctuates considerably because the load torque is pulsated. When the frequency of the torque pulsation is close to the resonant frequency of the mechanical system, large vibration and acoustic noise are produced especially in the low-frequency region. This paper proposes a method to suppress the variation of the rotational speed of the V/F controlled induction motor with a fluctuated load by feedforward compensation using a timing sensor of 1 pulse/rev, considering that the load torque varies periodically. The feedforward data by a period for the compensation is obtained by the learning control based on the repetitive control in which the motor speed is controlled by periodically reflecting the past speed error on the present V/F input to the inverter. Effectiveness of the proposed method is confirmed by approximate analysis, simulations and experiments.     

内置式永磁同步电机不同转子拓扑结构对电机性能的影响分析

为了研究不同转子拓扑结构对8极48槽内置式永磁同步电机(IPMSM)的电磁性能和噪声性能的影响,分别建立了单层无隔磁桥、单层有隔磁桥、双层无隔磁桥以及双层有隔磁桥转子拓扑结构的内置式永磁同步电机的有限元模型。除转子拓扑结构以外,四种电机的定子拓扑结构、永磁体使用量等其它条件完全相同。首先,对电机电磁性能和噪声性能进行相关的理论分析。其次,建立四种电机的有限元模型,对四种电机的凸极率、输出转矩、转矩脉动以及空载反电势谐波畸变率等电磁性能进行比较分析,并对四种电机进行模态分析。最后,比较了四种电机的振动响应和噪声特性。结果表明,双层有隔磁桥转子结构的内置式永磁同步电机电磁性能最好,并且其噪声削弱效果也最好。     

Current harmonics and acoustic noise in AC adjustable-speed drives

AC adjustable-speed drives (ASDs) are finding increased opportunities for applications in which acoustic noise is a major consideration for acceptability. The major source of noise in an ASD is the excitation of the motor by nonsinusoidal currents. For load characteristics that simulate the performance required for fans and compressors, ASDs based on induction motors, permanent-magnet motors, and switched reluctance motors have been examined for correlation between current and acoustic noise. The effects that the specific types of noise produced by drives have on human subjects is examined with regard to temporary and permanent hearing-threshold shifts     

Y2-160二极电机降低电磁噪声的设计改进

针对二极11kW～18.5kW电动机电磁噪声偏大,参考国外二极电机的槽配合,改原30/26的槽配合为36/28,使Y2-160 4kW～7.5kW电机的电磁噪声处于令人满意水平.     

Reducing Acoustic Noise of Axial‐Gap SRMs by Decreasing Axial Electromagnetic Force Ripple

Switched reluctance (SR) motors are motors that utilize the reluctance torque originating in the magnetic saliency between the stator and the rotor, which are made up of an electromagnetic steel sheet and windings without a permanent magnet. Because of their robustness and simple structure, SR motors are suited for use as the in‐wheel motor for traction motors of vehicles. In a flat space such as is present in in‐wheel motors, the axial‐gap structure has an advantage compared with the conventional radial‐gap structure for the space factor of a motor. An axial‐gap in‐wheel SR motor was tested in a microbus, and the bus could be successfully driven. The test results regarding the motor performance were satisfactory. However, the motor emits a loud sound. The acoustic noise of the axial‐gap SR motor is mainly caused by the axial electromagnetic force. This paper presents a method of reducing acoustic noise that is based on a model of the electromagnetic force on the axial‐gap SR motor.     

Specifying and measuring the noise level of electric motors inoperation

A sound intensity noise testing approach specifically for rotating electrical machinery is described. The method achieves accurate results in the presence of other noise sources and in acoustical environments that are suitable for noise testing via conventional procedures. Tests have been performed on actual motors to demonstrate the method, and results are presented to illustrate its validity. It is concluded that loaded motors can be successfully tested for noise output, and it is urged that IEEE noise testing standards be expanded to cover the testing of loaded machines, including use of the sound intensity method     

基于频谱分析的±800 kV换流站噪声特性

因环境治理要求,开展对特高压换流站的噪声特性研究。通过采集±800 kV换流站户外换流变压器的风机空气动力噪声、平波电抗器的电磁噪声、交/直流滤波器场的电磁噪声的声压信号,分析了负载条件下各位置噪声声压信号的频谱特性,给出各噪声信号的低频段及A声级噪声值。测试结果表明,换流站噪声覆盖低、中、高频段,各类噪声频谱特征较为类似;低频段能量占噪声总能量的比率更大,同一测试条件下风机的低频噪声值远高于其他换流站户外设备。