VVT常见故障分析

基于VVT的基本原理,介绍了常见VVT故障,阐述了出现这些故障的原因,并总结常见VVT故障的检查方法。     

浅析计算机软硬件故障的防治方法

随着计算机技术的发展与普及，使得计算机在我们的生产生活中发挥着越来越重要的作用。然而在计算机的使用过程中，往往出现由于设备使用不当或意外受损等故障。因此，若要准确快速地排除计算机故障，就要求我们必须掌握一定的基本理论知识和故障处理技巧。本文主要是对我国计算机软硬件故障的防治现状进行探讨分析，从中找出问题所在，并提出相应的解决措施。     

煤矿违序开采带来的危害

违序开采带来安全隐患和经济效益的负面影响,对煤炭资源造成浪费,增加成本投入,对煤矿发展不利。文章针对违序开采带来的安全隐患,提出了具体的预防措施。     

Recent progress on decoupling diagnosis of hybrid failures in gear transmission systems using vibration sensor signal: A review

Reliable recognition of fault type and assessment of fault severity is essential for decision making in condition-based maintenance of gear transmission systems. In engineering practice, the gear systems are often subject to hybrid faults on the same component or different components. The concurrence of multiple faults makes the fault detection, in particular, the examination of both the fault types and severities, more challenging. Recently, this research area has been recognized as an important direction. A logic solution is to decouple the hybrid faults. This paper reviews various aspects of recent research in decoupling diagnosis of hybrid faults in gear transmission systems, and discusses the techniques used for gearbox hybrid faults decoupling. The general fault detection technologies for gearboxes are also briefly summarized. A potential methodology based on the bounded component analysis (BCA) for hybrid faults decoupling is discussed. Possible future research trends of gearbox hybrid faults decoupling diagnosis are suggested.     

Probabilistic Wavelet Fuzzy Neural Network based reactive power control for grid-connected three-phase PV system during grid faults

This study presents a reactive power controller using Probabilistic Wavelet Fuzzy Neural Network (PWFNN) for grid-connected three-phase PhotoVoltaic (PV) system during grid faults. The controller also considers the ratio of the injected reactive current to meet the Low Voltage Ride Through (LVRT) regulation. Moreover, the balance of the active power between the PV panel and the grid-connected inverter during grid faults is controlled by the dc-link bus voltage. Furthermore, to reduce the risk of over-current during LVRT operation, a current limit is predefined for the injection of reactive current. The main contribution of this study is the introduction of the PWFNN controller for reactive and active power control that provides LVRT operation with power balance under various grid fault conditions. Finally, some experimental tests are realized to validate the effectiveness of the proposed controller.     

机电设备的常见故障与维修方法探析

在日常工作中若要确保机电设备处于正常有效的工作状态,则需要结合设备的常见故障,采取相应的措施,以确保设备出现故障时可及时维修,不影响日常工作。本研究通过阐述机电设备在维修方面的重要作用,分析机电设备在运行期间较为多见的故障事件,并提出相应的应对策略,为机电设备的正常工作提供保障。     

感应电机转子故障特征在交直交变频器中的传播

为研究感应电机转子故障特征在交直交变频器中的传播规律,在感应电机由交直交变频器驱动的系统中,利用逆变器和整流器的开关函数,对感应电机发生转子断条故障时的逆变器直流侧电流和整流器交流侧电流进行了解析分析,发现了对应的故障特征频率分量。分别在感应电机转子一根断条和转子两根断条的情况进行试验,试验结果也证明了理论分析的正确性,这为从变频器的整流器交流侧诊断感应电机转子故障提供了理论依据。     

高压断路器在运行中的问题分析

高压断路器是电力系统不可缺少而使用广泛的电器，它是保证电力系统可靠运行的关键设备．由于电力系统的日益扩大，断路器在进行各种运行操作时会出现一些新问题，本文从理论上分析并联开断、近距故障开断和失步运行开断时的特点及可能产生延伸性故障的条件，说明提高断路器设计水平和加强断路器性能试验的重要性，使断路器的技术参数更为完善．     

FMS运行状态检测监控技术的研究

以柔性制造实验系统为研究对象，研究了ＦＭＳ检测监控系统的硬件体系结构和软件集成框架，提出了ＦＭＳ检测监控中信息的选择及故障处理策略，建立了基于专家系统和动态图形技术的ＦＭＳ运行状态检测监控系统，实现了运行状态的动态显示和故障的诊断。     

电力系统复杂故障通用算法的研究

我们用补偿法原理开发出电力系统复杂故障的通用计算软件。本文着重讨论其核心部分－故障后补偿导纳矩阵和故障前端口阻抗矩阵的形成，并推导出了有关计算公式。此程序可灵活地修改运行方式，对故障类型、故障特殊相、故障过渡电阻处理简便，易于编程。可满足电力系统继电保护整定计算和事故分析的需要。