Reliability Analysis of Electromechanical Systems with Degraded Components Containing Multiple Performance Parameters

Components of electromechanical systems usually contain multiple performance parameters and degrade over time. In previous studies, the reliability of these electromechanical systems was analyzed by the traditional method, and the system reliability was estimated based on the reliability of components and the structures of the systems. The system reliability estimated by the traditional method could not reflect the performance of the systems. A new method is proposed in this paper to analyze the system reliability according to the data of multiple performance degraded processes of components. The performance distribution of a degraded component is obtained by the performance degradation analysis, and then states of the component are defined and corresponding state probabilities are estimated. The universal generating function method is proposed and extended to compute the performance distribution and reliability of the system based on the performances of components. A numerical example illustrates the proposed method. The results of the example show that the proposed method can relate the performance of the system to the performances of components and absolutely reflect the relationship between reliability and performance. Compared with the exact values of the system reliability, the results obtained by the proposed method is almost the same with the exact values, and the results obtained by the traditional method are conservative. The proposed method overcomes the shortcomings of the traditional method and provides a new approach to analyze the reliability of electromechanical systems with degraded components containing multiple performance parameters.

Thermoelastoplastic Deformation Analysis of Electromechanical Equipments under Electrocaloric Shock

A coupled thermomechanical model is presented to investigate the thermoelastoplastic deformation mechanism of electromechanical equipments under the condition of electrocaloric shock. In the coupling model, differentiating from the previous analyzing viewpoint that looked upon deformation work as additional heat source, temperature-field equation is established by considering the weakening role of deformation work on the intensity of internal heat source; in the process of setting up displacement-field equation, G-derivative of nonlinear functional is introduced into the traditional theory of elastoplastic finite deformation to simplify the expression of structural stiffness; stress-field equation is constructed by using the least square method to improve the stress solution obtained by constitutive equation. The presented model is converted into finite element program to simulate deforming process of 3-D structures with temperature-dependent material properties. As an example, thermal deformation analysis of Shanghai metro cars’ brake resistor is performed and compared with experimental results for illustrating the validity of the presented model.

Analysis on the Application of Electrical New Technology of in Electromechanical Integration

The electrical new technology is a new frontier science.This kind of technology, with the development and progress of society, makes the continuous development and innovation.It is the future development trend of electrical engineering system,which plays a very important role in technological innovation.The principle and theoretical support for the development of electrical new technology includes Bio- electro magnetics, plasma physics, electromagnetic fluid mechanics and gas discharge physics etc.In addition, under the application of permanent magnetic materials and other new materials, the electrical new technology and obtained further development also promote the development and application of electronic power supply, strong magnetic field technology, solar photovoltaic power generation, and superconducting power technology.This paper mainly analyzes the application of electrical new technology in electromechanical integration.

Dynamics modeling and electromechanical coupling characteristics analysis of cage induction motors

Induction motors, as typical electromechanical energy conversion devices, have received limited attention in previous studies on electromechanical coupling vibrations, precise modeling, and the use of electromechanical coupling effects for fault diagnosis and condition assessment in motor drive systems. This study proposes a comprehensive model of cage induction motors that integrates the multiple coupled circuit model with a rotor-bearing dynamics model. The model accounts for the linear increase in the magnetomotive force across the slot and incorporates the skidding characteristics of bearings in the rotor-bearing system. By calculating the time-varying mutual inductance parameters based on the air-gap distribution in the vibration environment, the electromechanical coupling vibration of the cage motor is investigated. Furthermore, this study examines the electromechanical coupling vibration characteristics influenced by various factors, including bearing clearances, radial loads, and the vertical excitation frequencies of the stators. The results show that the proposed model improves the excitation inputs for the electrical and mechanical systems of the motor compared with conventional models. Increased bearing clearance and radial load affect the current and torque similarly but have opposite effects on the slip ratio. This study provides a deeper understanding of electromechanical coupling mechanisms and facilitates the use of such phenomena for fault diagnosis and condition assessment in motor-driven systems.

Three-Dimensional Isogeometric Analysis of Flexoelectricity with MATLAB Implementation

Flexoelectricity is a general electromechanical phenomenon where the electric polarization exhibits a linear dependency to the gradient of mechanical strain and vice versa.The truncated pyramid compression test is among the most common setups to estimate the flexoelectric effect.We present a three-dimensional isogeometric formulation of flexoelectricity with its MATLAB implementation for a truncated pyramid setup.Besides educational purposes,this paper presents a precise computational model to illustrate how the localization of strain gradients around pyramidal boundary shapes contributes in generation of electrical energy.The MATLAB code is supposed to help learners in the Isogeometric Analysis and Finite Elements Methods community to learn how to solve a fully coupled problem,which requires higher order approximations,numerically.The complete MATLAB code which is available as source code distributed under a BSD-style license,is provided in the part of Supplementary Materials of the paper.

Global coupled equations for dynamic analysis of planishing mill

The dynamic properties of rolling mill are significantly influenced by many coupling factors. According to the coupled mechanical and electric dynamics theory, the global coupled equations for the dynamic analysis of planishing mill CM04 of Shanghai Baosteel Group Corporation were derived, by using finite element methods. These elasto-dynamic equations establish the coupling relations among the stand vibration system, torsional vibration system, driving motors, etc. It provides theoretical basis to a certain extent for globally dynamic simulation, analysis of stability of motion, prediction of abnormal operating mode, globally optimum design and control, etc.

一种机载机电系统语音告警故障分析与检测

飞机上,机电管理计算机完成与机电系统和航电系统之间的信息交互,对保证飞机安全飞行起着至关重要的作用。本文主要讨论基于机电管理计算机的机电系统语音告警机理。针对飞行过程中,发生的语音告警,进行故障检查和机理分析,针对报出的总线访问超时故障,完成故障定位并提出解决方案。为之后保证飞机安全飞行和机电管理计算机的研制和保障提供重要支撑。

总相位滞后角-延时关系下的电子机械制动主控制器控制方法

电子机械制动(electromechanical brake,EMB)的主控制器延时受到多种因素的影响,影响因素与延时控制之间存在复杂的交互作用,导致对其延时控制具有较高难度。为此,提出了一种电子机械制动主控制器延时控制方法。综合考虑电机堵转转矩、电机摩擦、传动机构和制动机构等因素对电子机械制动的影响,分析制动系统的延时与滞后角的相互关系。计算主控制器延时与电子机械制动的总相位滞后角量化关系,通过状态观测器获取其估计值,利用电机转子的转动惯量、摩擦力矩、传动和制动方程获取EMB的制动状态,结合主控制器估计增益参数,实现延时的主动控制。实验结果表明,所提方法应用下主控制器的延时控制耗时较短,电子机械制动距离和滑移率得以明显降低,说明该方法能够有效地保障电子机械制动的稳定性。

电力系统风力发电建模与仿真研究综述

对于大规模风电并网的电力系统安全稳定分析,构建合适准确的风电场模型至关重要。首先,梳理了现有风电机组的模型结构以及风电场的动态等值,阐述了风力发电系统的参数辨识方法。其次,介绍了电力系统中风力发电系统常用的时域仿真分析技术,主要综述了电磁暂态仿真、机电暂态仿真、中长期动态仿真、机电-电磁暂态混合仿真和数模混合仿真技术。然后,简述了风力发电系统建模与仿真的新进展。最后,分析了电力系统中风力发电系统的建模及其仿真技术面临的挑战与瓶颈,并结合新型电力系统的需求,对其建模与仿真技术进行了展望。

温变下基于奇异谱分析的机电阻抗损伤识别法

为消除温度变化对损伤识别的影响,采用奇异谱分析(singular spectrum analysis,简称SSA)方法处理阻抗信号以分离不受温度变化影响的信号分量,提出结合t-分布随机邻域嵌入(t-distribution stochastic neighbor embedding,简称t-SNE)与K均值聚类算法的无监督机器学习方法,进一步处理信号分量实现损伤识别。为验证该方法的可行性,以螺栓组连接的铝板结构作为实验对象进行温度变化工况下螺栓松动机电阻抗损伤识别实验。结果表明,应用SSA方法得到的信号分量能在温度变化影响下有效识别螺栓松动状态,各工况识别准确率均达到98%以上,证明了所提出方法对消除温度变化影响的有效性。

基于静止无功发生器详细模型的机电暂态仿真适应性分析

机电暂态仿真是大电网分析的重要工具。现有电力电子设备的机电暂态模型一般呈现理想电流源特性,无法体现设备自身稳定性及能力约束对于系统暂态特性的影响。在电力电子化电力系统背景下,以上不足降低了仿真准确性,制约了电网运行极限制定与新能源送出能力。文中基于旋转坐标系推导了静止无功发生器及控制系统的标幺化数学模型,并建立了对应的机电暂态模型。在建模精度与电磁暂态模型一致的前提下,通过模态分析法对比了机电暂态仿真与电磁暂态仿真的主要差异,揭示了机电暂态仿真的能力边界与适用范围。结果表明,机电暂态仿真能够揭示与工频能量流有关的功角、频率、电压稳定特性,而不能反映与电网动态强相关的谐振或者宽频振荡特性。

一种用于MEMS加速度计温度性能提升的双质量全差分结构

微电子机械系统(MEMS)加速度计作为应力敏感器件,很容易受到外界应力的影响,尤其是对温度应力非常敏感,MEMS加速度计的温度性能成为了制约加速度计性能提升的关键因素。为了提高MEMS加速度计的温度性能,减小温度漂移,提出了一种新型的双质量、全差分MEMS敏感结构方案。通过双质量的差分效果,可以将外界温度变化引起的变形差分掉,从而降低加速度计的温度系数,提高温度性能。利用有限元仿真的手段,优化双质量结构的布局,验证加速度计的温度漂移结果。实验结果表明,加速度计温度性能得到了有效提升。

基于大数据分析的矿山机电设备故障诊断与预测

矿山机电设备的故障诊断和预测对于矿山的安全和生产效率具有重要意义。传统的故障诊断方法往往依赖于经验和人工分析,存在着准确性低、实时性差等问题。随着大数据技术的快速发展,大数据分析在矿山机电设备故障诊断与预测中展现出巨大潜力。本文旨在深入探讨大数据分析在该领域中的优势和关键技术,并通过一个具体的应用案例展示其实际应用效果。

大型泵站机电设备安装分析及措施

大型泵站机电设备的安装质量对于确保泵站的正常运行至关重要。然而,由于机电设备的复杂性和多样性,安装过程中会遇到一系列问题。通过分析南水北调东线八里湾泵站机电设备运输安装过程中遇到的问题,提出了相应的解决方案和措施。对泵站机电设备安装问题进行深入研究和分析,可以为泵站安装及运维人员提供借鉴和建议。

运行方式改变后弱阻尼特征模式的快速计算方法

随着新能源与柔性负荷的大规模接入,电力系统运行方式实时变化,弱阻尼特征模式的阻尼特性亦随之改变。为有效评估实际系统的动态稳定性,传统QR法精度高,但速度难以满足弱阻尼特征模式的在线追踪需求。为此,针对运行方式改变后弱阻尼模式的模态特性,基于发电机惯量等值提出一种状态量的分群聚合方法,利用机电振荡模式的状态空间降维映射,实现弱阻尼特征模式的快速搜索。为保证所得特征模式的可靠性,提出了主导群相关因子指标,对状态量分群变化场景自适应选择精确的QR法,并由此构建弱阻尼特征模式计算框架,以解决实际系统特征值计算中存在的模式匹配与模态时变问题。与QR算法的对比验证了所提方法的快速性与准确性。

COMSOL中挠曲电圆筒的力电耦合行为分析

针对目前商业有限元软件中缺少挠曲电模块且有限元自主编程数值模拟挠曲电问题的复杂性问题,提出在COMSOL软件中的偏微分方程模块(PDE模块),对考虑挠曲电效应的力电耦合问题直接进行数值模拟的方法.首先,通过数值计算固定边界位移的挠曲电圆筒,验证有限元数值计算方法的正确性.接着,研究挠曲电系数和不同材料梯度指数对圆筒力电耦合的影响.数值结果表明:在微米尺度下,增大挠曲电系数对径向位移的影响很小,但是对圆筒内部的电势和电位移分布影响很大.增大材料梯度指数对挠曲电圆筒内部力电耦合影响非常明显,圆筒内部径向位移相对边界处变化范围逐渐减小,圆筒内部电势呈现负值逐渐减小后转为正数的趋势,而圆筒内部电位移值负值逐渐增大.本工作可以为挠曲电效应数值计算及挠曲电结构设计提供帮助.

基于物联网的机电设备远程监控系统设计与实现

探讨了基于物联网技术的煤矿机电设备远程监控系统的设计与实现,介绍了系统的总体架构,包括传感层、传输层、处理层和用户界面层,讨论了关键组件的选择,如耐用传感器、可靠的数据传输技术以及高效的数据处理和分析平台。分析认为,采用物联网技术对煤矿机电设备进行监控,能够有效减少设备故障,降低维护成本,提高生产效率和安全性。

煤矿机电大型设备噪声与振动分析及优化控制策略研究

针对煤矿机电大型设备中噪声与振动问题,主要深入分析了噪声与振动的来源与影响,采用声级计、加速度计等测试方法对设备进行监测,并通过频率分析、时域分析等技术处理测试数据。并进一步提出了减振设计、降噪措施以及智能控制策略,旨在实现对煤矿大型机电设备的优化控制。通过仿真实验,验证了这些优化控制策略的有效性,为改善矿工作环境和提升设备性能提供了科学依据。

铁路隧道防灾疏散救援机电设备及监控系统设计应用现状及提升方向

长大铁路隧道远离城市区域,对灾害的控制和应急救援要求设置防灾疏散救援机电设备和监控系统。文章首先论述了铁路隧道防灾疏散救援工程设计发展沿革及技术体系,介绍了所涵盖的机电设备与监控系统的设计、应用现状,分析了不同类型机电设备和监控系统的实际需求与可靠性,针对监控系统设计给出了五方面建议,并指出铁路隧道防灾疏散救援机电设备与监控系统的提升方向。

基于铁谱分析的煤矿机电设备摩擦磨损状态分析算法研究

介绍一种基于铁谱分析的煤矿机电设备摩擦磨损状态分析算法。该算法主要通过对设备铁谱图像的预处理,提取设备最大块磨损颗粒的多元特征,利用各方面特征的对比,判断机电设备摩擦磨损状态。通过铁谱分析监测煤矿机电设备摩擦磨损状态,为煤矿机电设备运维管理提供支持,确认铁谱分析的应用价值。