状态检测诊断技术在检修设备上的应用

1状态检测技术在设备上的应用 1.1利用电动机故障检测仪对电机电感(L)、阻抗(Z)及绝缘进行检测 正常状态下的电动机检测周期可为一个月,这时的电机三相绕组电感值和阻抗平衡且稳定.经过长时间的检测,即可根据所积累的数据确定相对标准参考值.结合电机的功率,我们制定了以下相对标准:     

光伏系统中蓄电池充放电控制方案的探讨

该文对现行光伏系统中蓄电池充放电控制方案进行了分析。决定一个充电器性能的关键是其电压外环检测的精确度。普通的在线式电压检测方法由于无法完全满足蓄电池的充电特性，因此在提高蓄电池充电器的整体效能以及在提高蓄电池寿命方面造成瓶颈。针对电压环检测存在的问题，在本文中提出了一种新颖的检测方案——离线式检测，并用实验证明了新的离线式检测方案能进一步提高蓄电池的寿命。     

机车铅酸蓄电池检测技术及开发应用

通过对赏蓄电池检测技术的分析,提出使用固定频率交流电测量蓄电池电导的方法检测蓄电池容量,成功研制QTK-Ⅱ型便携式电池检测仪,不论在线还是离线,均能判断畜电池状态的优劣,为铁路机车铅酸蓄电池的日常检测保养提供科学方法.     

一种新的舰船燃气轮机状态监测系统

本文描述了一种新的舰船燃气轮机状态监测系统。该系统综合了先进的状态监测、性能分析、预测方法。利用专用模块进行在线或离线的燃气轮机性能监测／预测／诊断、传感器故障检测、故障及事件存储并提供维修措施。     

一种内燃机车蓄电池检测仪

介绍用一种蓄电池动态检测仪检测出落后单节的方法。此方法简单可靠 ,可有效检测出落后单节 ,便于排除蓄电池组的故障     

线路状态检测仪在机车电路检修中的应用

分析了内燃机车电气线路故障产生的原因和造成的后果,提出了利用线路状态检测仪在线检测的方法,及时发现和处理电气线路的隐患。     

提高牵引电动机电枢轴承可靠性的探讨

对牵引电动机轴承的几种常见的故障进行了分析,并对提高牵引电动机电枢轴承运行可靠性从装配工艺和检测方面提出了建议.     

柴油机高压燃油系统原位校正仪的设计

针对现有柴油机高压燃油系统检测方法的缺点,设计了柴油机高压燃油系统原位校正仪,以及相应的软件系统.此检测仪可对柴油机油压信号进行采集、处理、存储以及显示,根据波形数据计算出柴油机工作的各项参数,并结合故障特征波形可对柴油机进行故障诊断.检测过程完全由软件程控,无任何硬开关设置,实现了柴油机高压燃油系统的原位校正.     

基于CNN优化的蓄热式电锅炉供暖系统容错控制方法

为了提升容错控制效果,降低运行成本,保证供暖系统供热稳定性,研究基于CNN优化的蓄热式电锅炉供暖系统容错控制方法.优化CNN中不同尺度卷积核卷积输入的供暖系统信号,利用lesky-relu激活函数提取卷积信号内的故障信息,得到故障特征图,实现蓄热式电锅炉供暖故障检测;依据内模原理,结合故障检测结果,设计故障补偿器,降低...     

煤矿刮板输送机电动机损坏的原因及预防措施

本文对煤矿井下生产运输设备所用电动机损坏的原因进行了分析,就如何预防电动机出现故障提出了几项措施.     

A Reconfigurable Motor for Experimental Emulation of Stator Winding Interturn and Broken Bar Faults in Polyphase Induction Machines

The benefits and drawbacks of a 5-hp reconfigurable induction motor, which was designed for experimental emulation of stator winding interturn and broken rotor bar faults, are presented in this paper. It was perceived that this motor had the potential of quick and easy reconfiguration to produce the desired stator and rotor faults in a variety of different fault combinations. Hence, this motor was anticipated to make a useful test bed for evaluation of the efficacy of existing and new motor fault diagnostics techniques and not the study of insulation failure mechanisms. Accordingly, it was anticipated that this reconfigurable motor would eliminate the need to permanently destroy machine components such as stator windings or rotor bars when acquiring data from a faulty machine for fault diagnostic purposes. Experimental results under healthy and various faulty conditions are presented in this paper, including issues associated with rotor bar-end ring contact resistances that showed the drawbacks of this motor in so far as emulation of rotor bar breakages. However, emulation of stator-turn fault scenarios was successfully accomplished.      

多功能局部放电检测仪的应用研究

介绍了基于超声波测量法的多功能局部放电测量设备的工作原理,以两个实例分析了多功能局部放电检测仪在实际应用中的可靠性.结果表明,该设备能够很好地检测和定位出利用其他局部放电检测手段无法检测到的局部放电信号,具有较高的可靠性.     

Automatic diagnosis and location of open-switch fault in brushless DC motor drives using wavelets and neuro-fuzzy systems

The faulty performance of permanent-magnet (PM) brushless dc motor drives is studied under open-switch conditions. The wavelet transform is used to extract diagnostic indices from the current waveform of the motor dc link. An intelligent agent based on adaptive neuro-fuzzy inference systems (ANFIS) is developed to automate the fault identification and location process. ANFIS is trained offline using simulation results under various healthy and faulty conditions obtained from a lumped-parameter, network model. ANFIS testing shows that the system could not only detect the open-switch fault, but also identify the faulty switch. Good agreement between simulation results and measured waveforms confirms the effectiveness of the proposed methodology.     

Improved Resolution of the MCSA Method Via Hilbert Transform, Enabling the Diagnosis of Rotor Asymmetries at Very Low Slip

This paper proposes an online/offline induction motor current signature analysis (MCSA) with advanced signal-and-data-processing algorithms, based on the Hilbert transform. MCSA is a method for motor diagnosis with stator-current signals. Although it is one of the most powerful online methods for diagnosing motor faults, it has some drawbacks that can degrade the performance and accuracy of a motor-diagnosis system. In particular, it is very difficult to detect broken rotor bars when the motor is operating at low slip or under no load, due to fast Fourier transform (FFT) frequency leakage and the small amplitude of the current components related to the fault. Therefore, advanced signal-and-data-processing algorithms are proposed. They consist of a proper sample selection algorithm, a Hilbert transformation of the stator-sampled current, and spectral analysis via FFT of the modulus of the resultant time-dependent vector modulus for achieving MCSA efficiently. Experimental results obtained on a 1.1-kW three-phase squirrel-cage induction motor are discussed.      

不同工况下3.3 MW永磁直驱风力发电机电磁场仿真分析及损耗修正

文章设计了一台3.3 MW外转子表贴式永磁直驱风力发电机,并对其电磁性能及短路故障情况进行了有限元仿真分析。首先,得出了这台电机在额定工况下的转矩和磁密分布等结果,以及在相间绕组短路和三相绕组短路两种情况下电机转矩、电压和电流等曲线的变化情况;然后,通过三维静磁场仿真,探究了电机定子的径向通风道结构对二维有限元仿真的影响程度,并对铁耗进行了修正;最后,通过电磁场-温度场的耦合迭代仿真,考虑了温度场影响下的电机内部材料特性的变化对电机损耗结果的影响。     

高压共轨柴油机喷油器电磁阀故障诊断系统设计

根据电磁阀驱动回路仿真及试验,得出了高压共轨柴油机喷油器电磁阀在正常工作时以及短路、断路等各种故障状态时的驱动电流特性。根据对这些情况下驱动电流特征的对比,采用软件与硬件相结合的方法,设计了高压共轨柴油机喷油器电磁阀实时故障检测系统。该系统能够检测电磁阀的不同故障并且能在电磁阀故障时实现ECU的自保护功能。试验证明,该方法是一种实用而且快速的电磁阀故障检测方法。     

基于MEMS电场传感器的1000 kV非接触验电器研究

为解决交流特高压输电线路验电难题,基于微机电系统(MEMS)电场传感器及非接触式验电器的工作原理,通过仿真计算确定了档中、塔头位置的验电区域及验电器报警阈值要求,结合试验对MEMS非接触式验电器报警阈值进行了校准,并在特高压线路开展了非接触式验电器的现场应用。结果表明,当MEMS非接触式验电器报警阈值设定为25kV/m,档中位置时验电器置于距离导线10～15m的区域内、塔头位置时验电器朝导线方向伸出距离塔身、横担2m区域即可准确判断线路带电情况。     

Design and testing of a four-phase fault-tolerant permanent-magnet machine for an engine fuel pump

This paper discusses the design and testing of an aircraft electric fuel pump drive. The drive is a modular, four-phase, fault-tolerant system which is designed to meet the specification with a fault in any one of the phases. The motor employed has a permanent-magnet rotor with the magnets arranged in a Halbach array to maximize the air-gap flux density. Exceptionally high electric loadings are obtained by flooding the entire motor with aircraft fuel, which acts as an excellent cooling agent. Theoretical results are compared with test results gained in conditions approaching those found in an aircraft. Tests are carried out on the unfaulted drive and with one of several fault scenarios imposed. The electrical and thermal performance of the drive is assessed, showing how the flooded fuel cooling has excellent performance without introducing significant drag on the rotor.     

A robust control method for a PV-supplied DC motor using universal learning networks

In this paper, a new robust control method and its application to a photovoltaic (PV) supplied, separately excited DC motor loaded with a constant torque is discussed. The robust controller is designed against the load torque changes by using the first and second ordered derivatives of the universal learning networks (ULNs). These derivatives are calculated using the forward propagation algorithm, which is considered as an extended version of real time recurrent learning (RTRL). In this application, two ULNs are used: The first is the ULN identifier trained offline to emulate the dynamic performance of the DC motor system. The second is the ULN controller, which is trained online not only to make the motor speed follow a selected reference signal, but also to make the overall system operate at the maximum power point of the PV source. To investigate the effectiveness of the proposed robust control method, the simulation is carried out at four different values of the robustness coefficient γ in two different stages: The training stage, in which the simulation is done for a constant load torque. And the control stage, in which the controller performance is obtained when the load torque is changed. The simulation results showed that the robustness of the control system is improved although the motor load torque at the control stage is different from that at the training stage.