基于永磁同步电机和电磁轴承的人工心脏研究

提出了的新型可植入式人工心脏是由轴向磁场结构的永磁同步电动机直接发驱动。电机转子安装在人工心脏泵的叶轮上,并因电磁轴承的作用而悬浮。文中将重点分析该电机及轴承的结构与设计,并给出了一些相关的仿直结果。     

磁悬浮人工心脏驱动电机的优化设计

提出了基于电磁场有限元分析技术,对磁悬浮人工心脏的驱动电机进行优化设计的方法。根据对人工脏器的设计要求,设计了一台单面轴隙式永磁无刷直流电机作为人工心脏的驱动电机。通过建立驱动电机的3D整体模型,研究电机气隙中的磁场分布。同时结合电机损耗的计算方法,以提高电机的总体效率、降低电机的整体尺寸为目标,对驱动电机的电机线圈、永磁体阵列的尺寸进行优化设计。仿真与计算得出的优化设计结果,可以为人工心脏的工程设计提供参考。     

Torque characteristics and application of two‐phase induction motor driven by two power supplies with nearby frequencies

When two power supplies with nearby frequencies are connected to a two‐phase induction motor, the motor generates two kinds of oscillatory torque components, which have frequency components of the sum and the difference between the frequencies of the power supplies. These oscillatory torque components are sinusoidal, and the torque with the frequency component of the difference is considerably larger than the torque with the frequency component of the summation. Consequently, the motor behaves as a swing motor, which alternately changes the direction of rotation. Because of the regularity of the period of the human heartbeat, this swing motor is suitable for use as the driver of an artificial heart. We propose here to use this swing motor as the pump for artificial hearts. In this paper, we present the fundamental theory and the characteristics of the swing motor, and an outline of the motor action for artificial hearts. © 2000 Scripta Technica, Electr Eng Jpn, 132(1): 73–80, 2000     

基于ACGAN和模型融合的电机轴承故障诊断方法

电机轴承疲劳试验成本较高和故障数据不足导致利用机器学习等人工智能算法进行故障诊断时效果不佳。另外,单一模型对电机轴承故障诊断的准确率也较低。为解决这两个问题,提出了一种结合辅助分类器生成对抗网络(ACGAN)和模型融合的电机轴承故障诊断方法。首先将采集到的振动数据转换为二维灰度图,对每个灰度图添加标签后输入ACGAN模型,生成大量与原始数据高度拟合的新样本。然后将新样本与原始样本混合,经数据降维后输入由6个基学习器和1个元学习器融合而成的模型中。最后由融合模型输出诊断结果。试验证明,ACGAN和模型融合能有效提高电机轴承故障诊断的准确率。     

Design investigation of a linear motor for artificial heart driving

The authors have been considering the use of a linear pulse motor (LPM) as a driving source of a totally implantable artificial heart (TAH), and have developed a series of artificial heart models that incorporate such a motor. The newly developed linear-type TAH (linear TAH) has two blood-pumps, which are inflated and deflated alternately by the LPM, causing a pusher plate to pulsate the blood. This paper deals with the performance calculation of the LPM using the loading ratio. Some motors manufactured for driving TAHs were then selected to compare their machine parameters. The selected motors were LPM, linear oscillatory actuator, brushless dc motors, and ultrasonic motor. Two parameters were selected for the comparison: the mechanical output/volume ratio and the motor constant. The results may be summarized as follows: 1. The LPM was designed based on the loading ratio, and the kinetic thrust and velocity were obtained at the range of 77 newtons and 80 mm/s, respectively. 2. The loading ratio of the LPMs were more than eight times larger in comparison with the rotary motors that were used in industrial machines. 3. The motor constants of the LPMs were recognized to be one figure larger than that of the brushless dc motors. In order to reduce the volume of the linear TAH, it is necessary to increase the drive velocity of the LPMs. Application of the linear motor to a nonpulsatile artificial heart will be one way to achieve this. © 1998 Scripta Technica, Electr Eng Jpn, 123(1): 43–50, 1998     

无刷直流电动机在轴流式血泵系统中的应用

根据人工心脏轴流式血泵系统的特殊要求，对所采用的微型无刷直流电动机的设计方法和关键参数进行了分析探讨，针对电机高速运行时定子齿存在的严重的磁饱和问题，提出将电机定子部分设计为三齿槽，并采用DSP实现了电机的无位置传感器控制。仿真和实验结果表明，该电机良好的起动特性和机械特性基本能够满足轴流式血泵系统的要求。     

基于免疫克隆优化的阴性选择算法在电机故障检测中的应用

阴性选择算法(NSA)和免疫克隆选择算法是两种典型的人工免疫系统。首先介绍了阴性选择算法和免疫克隆算法的基本原理,由于阴性选择算法的检测器存在大量无法检测的黑洞。采用免疫克隆优化算法对阴性选择算法生成的检测器进行优化,以提高故障检测率。最后通过检测电机的故障轴承证明了方法的有效性。     

轴流式血泵无位置传感器控制的设计

介绍了一种用于人工心脏轴流式血泵无位置传感器永磁无刷直流电机闭环调速控制系统的设计,该设计利用自起动方式实现电机起动,当电机达到额定转速时,进入闭环控制系统,利用反电势逻辑积分法,实现无刷直流电机无位置传感器控制。     

小型无刷直流电动机无位置传感器控制的设计

介绍一种用于人工心脏轴流式血泵的无位置传感器无刷直流电动机闭环调速控制系统的电路设计。利用自起动方式实现电机起动，当电机达到额定转速时进入闭环控制系统，利用反电势逻辑积分法，实现无刷直流电动机无位置传感器控制。     

一种用于人工心脏的无轴承无刷永磁直流电动机的设计与特性

置入体内的人工心脏血泵驱劝电机要求具有高效和高力能密度，以便最大限度地减小电机及其供电蓄电池的体积与重量，本文介绍的一种ＩＶＡＳ系统，采用血泵与驱动电机为一体的无轴承结构，永磁电机的定转子兼作轴向磁力止推轴承，并为血泵运转的动态稳定提供径向磁平衡力，电机为外转子结构，永磁体采用Ｈａｂａｃｈ阵列，以提高气隙磁通密度，定子采用闭口槽，以消除转矩脉动和提高电机出力。     

An evaluation of the electrostatic shielded induction motor: asolution for rotor shaft voltage buildup and bearing current

This paper evaluates a new induction motor, the electrostatic shielded induction motor (ESIM). An ESIM reduces rotor shaft voltages to levels below the bearing lubricant's electric field intensity breakdown level and offers one solution to accelerated bearing wear caused by fluting induced by pulsewidth modulated (PWM) inverters. The paper begins by reviewing shaft voltages and the resulting bearing currents when operated on PWM voltage source inverters. An example of bearing fluting is shown, and system models are presented and discussed. The construction details and test results for several ESIMs are presented. Experimental results show the ESIM solves the electrostatically induced rotor shaft voltage and bearing problem without degrading the electromagnetic performance of the motor     

Motor shaft voltages and bearing currents and their reduction inmultilevel medium-voltage PWM voltage-source-inverter drive applications

This paper presents test results on problems and solutions of motor shaft voltages and bearing currents in medium-voltage pulsewidth modulated (PWM) drive systems. Tests show that multilevel medium-voltage PWM voltage-source inverter drives can cause motor bearing currents, similar to a low-voltage PWM drives, even with one motor bearing insulated. Common-mode voltages generated as a result of PWM switching are observed on motor windings and capacitively coupled to the motor shaft, leading to bearing currents. Potential solutions, including altering common-mode circuitry, changing the grounding scheme, providing common-mode filtering, and grounding the motor shaft, are investigated. Test results on their effectiveness are presented     

NEUTRAL-TO-GROUND VOLTAGE MINIMIZATION IN A PWM-RECTIFIER / INVERTER CONFIGURATION

ABSTRACT

High frequency common mode voltage produced by power converters are a major cause of conducted EMI, creating motor ground currents, bearing currents and other harmful by-products. In this paper a control algorithm for an induction motor fed by a fully controlled rectifier and inverter is developed to reduce the common mode neutral-to-ground voltage of the induction motor. A bearing current model is used to evaluate the effects on the bearing currents of the double bridge modulation scheme when the new algorithm and conventional algorithms are used. Simulation results are shown to demonstrate the benefits of the new PWM approach.     

潜油电机设计方法研究及验证

潜油电机是一种立式工作的特殊三相异步电动机,其结构细长,定转子采用分段结构,每两段定转子之间分别装有隔磁段和扶正轴承.显然普通三相异步电机的设计方法难以适用于潜油电机.修正了潜油电机端部漏抗和隔磁段漏抗的计算方法,并采用流体力学的基本理论,推导出了转子与润滑油之间的油摩损耗的计算公式,计算了扶正轴承中的涡流损耗,改进了潜油电机的设计方法.设计制造了两台样机,一台装有隔磁段,另一台没有隔磁段,旨在考核分段处结构对电机电磁参数和性能指标的影响.实验结果验证了所改进设计方法的正确性,同时得到隔磁段对电磁参数和性能存在较大影响,设计时应充分考虑.     

滑动轴承二极电动机的振动频谱分析

大功率的二极电机不少采用滑动轴承.与采用滚动轴承的电机不同,除电磁振动以外,采用滑动轴承的电机振动频谱要简单得多,大都是1倍、2倍、3倍和略低于1/2倍基频(50Hz)的振动.用电机振动谱的测试分析振动形成的原因,对提高振动测试分析水平有一定的意义.     

Oil mist lubricated bearings

This paper discusses the recent improvements in applications of motors. Oil mist lubrication is cost-effective method for lubricating electric motor bearings. Reliability can be improved by oil mist lubrication, provided with system analysis, motor insulation system compatibility, bearing and bearing housing has a though flow system to lubricate properly. Advances in the bearing housing sealing system has made an electric motor with oil mist lubrication an environmentally friendly motor.     

具有被动式磁力轴承的无刷直流电机研究

非接触式磁力轴承广泛用于高速电机及某些具有免维护要求的特殊应用场合，如人工心脏旋转血泵。该文介绍了一种具有被动式磁力轴承的新型无刷直流电机。采用该文提出的被动式磁力轴承，电机转子可实现磁悬浮而不需要进行悬浮力控制。电机转子的轴向稳定性依靠被动式轴承以及永磁转子由于轴向位移产生的轴向力来实现。电机转子的径向磁悬浮，需要通过对被动式磁力轴承永磁环以及无刷直流电机的气隙、永磁体的径向厚度和轴向长度的优化设计来实现。     

电机轴承的检修技术

电机轴承检修质量的好坏对电机的安全状况、经济运行、寿命的长短起着各种故障产生的原因以及相应的检修对策.     

PWM脉冲作用下电机轴电流产生机理分析

在分析电机内部分布参数的基础上，建立脉宽调制(PWM)逆变器驱动系统共模回路的等效电路，由此得到以共模电压形式存在的轴电压的计算公式。为研究轴承电流产生机理及存在形式，建立模拟轴承内部接触和轴承油层击穿的轴承模型。通过仿真分析轴承电流与脉冲电压上升时间、电机内部分布电容之间的关系。最后给出抑制电机轴电压与轴承电流的方法，并通过对比分析验证其有效性。