Design of networking condition monitoring andfault diagnosis for wind turbine transmission system

In order to solve the incipient fault diagnose problem of the transmission system, a networking condition monitoring and failure diagnosis system based on B/S and C/S hybrid architecture for wind turbine transmission system is designed in the paper. Firstly, the paper analyzes the demands of condition monitoring and fault diagnosis system for wind turbine transmission system, and designs its overall framework and function modules. Then, combining with the data acquisition equipment, by the .NET and SQL Server platform, the paper designs condition monitoring and failure diagnosis system for wind turbine transmission system, which includes the functions of networking data acquisition, remote condition monitoring, signal analysis, fault diagnosis and database as well. The system has been successfully applied to a condition monitoring and fault diagnosis of wind turbine transmission system.     

Application on Extracting Feature in State Monitoring and Fault Diagnosis

With the development and application of information and internet and virtual instrument technology ,the virtual globular company based on internet arises .To study remote state monitoring, remote fault detection and diagnosis about large scale, complicated and integrative equipment become very important. In the whole fault diagnosis system , the detecting ,data acquisition is original ,processing; transform and extracting features with the signal detected is a key factor. The theories and methods used in mechanical fault diagnosis is stated. The application of signal process and its feature extracting methods is introduced which are time domain, frequency domain and time frequency domain analysis, in state monitoring and fault diagnosis with its signal analysis. The processing method of random time variant special signal is given also.     

The Application of Fuzzy Neural Network in the Detection for Moving Object

A fuzzy neural network(FNN) of detection for moving object based on BP algorithm is described in this paper.The correctness of the FNN in signal detection for moving object and fault diagnosis for instrument is proved by experiments.     

Study on the Method of Intelligence Fault Diagnosis System for Drill

It is very difficult to simulate the motion process of drill by accurate mathematics model for the complexity and invisibility of stratum. The fault of drill is usually identified and disposed by personal experience so far. This means it can not estimate the trend of the equipment running good or not and the reason conduced the fault or location and degree of fault by data measured. Farther, it can not give the expert suggestions. Based on the studying of drill fault, artificial intelligence and expert system have been used in the petroleum drilling engineering, the theory and method of fault diagnosis intelligence system for drill have been studied. It also constitutes the expert knowledge database of graphic Fuzzy Neural Network for the familiar fault of drill. The intelligence reasoning machine which consists of expert rule, Fuzzy logic and artificial Neural Network have been bring forward. And the fault diagnosis system it makes for drill can be applied in complex system which includes multi-variable, multi-parameter and multi-process.     

State and Prospects of Diesel Engine Fault Diagnosis Technique

As a kind of complex power machinery, diesel engine is being paid more and more attention to its condition monitoring and fault diagnosis technology. In the fault diagnosis field of diesel engine, the technique of signal process, character abstraction and identification method have formed a system, but there is a certain distance away from practical. This paper analyzes the common faults and influencing factor of diesel engine. The principle, characteristic and disadvantage of modern fault diagnosis technology, such as various time-frequency methods based on vibration signal, speed fluctuation method, iron content and spectrometry, grey system theoretical diagnosis method, artificial neural network and expert system fault diagnosis method, were reviewed. The difficulties and the development direction of diesel engine fault diagnosis were put forward in the end.     

The Signals Analysis System Based on Fast Wavelet Transform

The fast wavelet transform (FWT) algorithm in wavelet analysis was introduced in the paper. With quadrature mirror filters (QMF) associated with popular wavelet bases, the fast wavelet decomposition and reconstruction for signals were implemented. Combined with virtual instrument technique, the FWT analysis system for signals was successfully developed. The system can break up signal not only into approximations, which are the high-scale and low-frequency components of the signal, but also into details which are the low-scale and high-frequency components. Especially it can identify singularity signal, which contain some important message of equipment condition and fault, and refine signal from noisy signal, which is corrupted by noise.     

Application of Self-tuning Models to Air Handling Units for Fault Detection

Building management control systems (BMCS) are widely employed in modern buildings. The huge amount of data available on central stations and outstations provide rich information for fault diagnosis of HVAC systems. An online fault diagnosis method for variable air volume air handling units was presented using self-tuning HVAC component models. The model parameters are tuned online by using a genetic algorithm (GA) which minimizes the error between measured and estimated performance data, so high modeling accuracy is assured. If the error between measured and estimated performance data exceeds preset thresholds, it means the occurrence of faults or abnormalities in the air handling unit system. The statistical method of selecting thresholds also is presented. The fault detection method was tested and validated using data collected from real HVAC systems. The results of validation show that the fault detection method can be integrated in BMCS systems to detect faults in air handling unit systems efficiently.     

全集成自动化控制系统在粮食储备库中的应用

结合粮库控制系统的设计及应用,概述全集成自动化技术在粮库中的应用,并对其关键技术进行详细说明。本文所设计控制系统实现了对粮食进仓、发放过程的自动监控、数据采集、故障诊断报警等功能。步进式提示防止误操作,减少人为失误;同时优化控制策略,减少设备停机次数,实现节能增效。实际运行效果表明该系统具有较强稳定性和优越性。     

The on line monitoring method of power transmission line fault basednon linear frequency response function

A novel method for power transmission line monitoring and fault diagnosis is proposed based on non linear frequency response analysis. The power line carrier signal has been used for on line monitoring of power transmission line. As the non linear frequency response function describes the system inherent characterization, different frequency response patterns corresponding to different operation states of transmission line can be established. Based on the analysis of transmission line characteristics of fault modes, various fault features can be extracted, thereby achieve online monitoring and fault diagnosis on transmission line. Simulation experiments show the effectiveness of the proposed method.     

A Method for Online Measurement of Dielectric Loss of HV Capacitive Equipment Insulation

It is still a major problem for research on online monitor dielectric dissipation factor of high voltage equipment insulation. In the field, new methods are paid attention by researchers especially. At present, there are no methods achieving the satisfactory measurement results. Based on the voltage and current at their respective zero crossed points, this paper proposes the integral measurement method which can be used to measure the dielectric dissipation factor of high voltage capacitive apparatus. The formula for dielectric dissipation factor angle computation is deduced by theoretical analysis and the computation results are achieved by digital simulation. Meanwhile, this paper explains the effect to measurements by system frequency, content of harmonic and zero-drift and draws the relevant error curves. It also proposes the measures to reduce the integral measurement method presented in this paper,which can convert measurement of small signal into that of big signal and accurately measure dielectric loss of capacitive apparatus. It also possesses great anti jamming ability under strong electromagnetic interference environment. The online measurement system can detect the dielectric dissipation factor of high voltage equipment by the integral measurement method.     

A fault data recording system design for hybrid electric vehicles

A data recording system for fault diagnosis of hybrid electric vehicles was studied by taking the integrated starter and generator (ISG) hybrid electric vehicle as the investigation object. The fault diagnosis communication net was established using a CAN bus and a K line. As designed, the system hardware structure included a CPU processing module, a communication module, and a USB recording module. With the system requirements and characteristics in mind, special circuit design and analysis of USB mass storage module were carried out based on the hardware scheme and software design. In the running test, the fault data recording system worked stably, and the data was recorded integrally and correctly. At the same time, the online display data accurately reflected the vehicle's running status.     

Leak Current Fault Diagnosis Problem-Solving in Launch Vihicle Controlling System

In point of view of the system, the characteristic of leak current fault diagnosis in launch vehicle controlling system is analyzed. It is presented that the fault is a connecting way for sytem factors. By building some basic concepts such as componts, syptoms, observation and faults, the system model is turned into graph, where nodes represent components and edges represent fault transmission among components. Besides,designing rule, that is, bisection rule for diagnosing alglorithm is given based on the information theory. Operating feasibility and entropy function characteristic are analyzed using component trade-off value to substitute component entropy, giving fault problem-solving way based on the drawing model.     

Principle and Scheme of a Feeder Automation Based System Protection

A new principle and scheme of a Feeder Automation based system protection using the channel of communication is proposed. The conjoint protection devices exchanging fault signal with direction information and the fault can be cleared instantly. These information can hel Pto isolate the fault zone and restructure the network rapidly. The recover is used for instantaneous faults. The optical MODEM disjoins the SCADA communication and Boolean signals functions using coding technology. So the fault flags can be exchanged rapidly peer-to-peer and special optical cables are not needed. Frames between optical MODEM are sent automatically. This scheme presented is successful through physical simulation experiment and has operated for about two years in a real distribution network.     

Study of Intelligent Fault Diagnostic System for a Kind of Power Plant

Based on the neural networks, object oriented technique, artificial intelligence technique and computer networks, an intelligent fault diagnosis system of the power plant whose need of the operation is presented. The architecture of software system , hardware system and corresponding databases is designed. The software of collecting data is established. The intelligent fault diagnosis system based on neural networks and object oriented technique is also developed. The physical system operation has been shown that the method mentioned above is feasible and effective in practice.     

Real time monitoring for multivariate statistical process with on line multiscale filtering

By analyzing shortages of current MSPCA model, an on line multi variable statistical process monitoring method is proposed, which uses some concepts from online multi scale filtering and can be applied to sensor fault diagnosis. In the method, wavelet decomposition is employed to the signals using edge correction filter in a fixed length data window, and then wavelet denoising is conducted with wavelet threshold filtering. Next, an on line multi scale model is constructed for data combining wavelet transformation and adaptive PCA in the previous data window. This model avoids time waste in direct signal denoising and reduces time cost in multi scale data with conventional PCA, which eventually increases accuracy in fault diagnosis. Experiments on eight vibration signals of 6135D diesel engine under severe leak condition prove the practicability and feasibility of the proposed method.     

design of an equipment condition monitoring and fault diagnosis network system for the main drive of a hot strip mill

A new distributed equipment condition monitoring and fault diagnosis network system based on an RS485 field bus and an industrial ethernet was designed for the main drive system of a hot strip mill. The system structure and composition were studied. The following problems were resolved: communication of an intelligence data acquisition module with RS485 interface; communication between a server, clients and a light emitting diode; and point to point communication between a programmable logic controller and server. Real time signals of 24 radial run out, 12 axial drifting can be synchronously acquisitioned and stored in a database. System operation is satisfactory and can be used to identify the causes of rolling mill halt and transmission slip brake, and to improve sheet metal quality.     

Application of Web Server in Remote and Intelligent On-line Diagnoses System for Rotational Machinery

Web Server is a software technology and communication method to carry out information issuance. The new concept of combination of equipment faults diagnoses with Web Services technology is proposed. The techniques flow of equipment, techniques parameters, signal characteristics and inference resolution in faults diagnoses are put forward with communication and software in order to carry out data dynamical exchange and interface of HMI. The remote processing on network of system information issuance is formed in this way. The principle and characteristics of Web Server technology are introduced. The common contents of information issuance in on line diagnoses system is also classified. The Web Server is applied in the project for high technology research work (863 project) "Remote and Intelligent On-line Diagnoses System for Rotational Machinery" to realize the function of information issuance and data inquire by groupware of DELPHI 6 Web Services.     

Development of the remote data supervisory system of the hybrid electric vehicle

Taking the hybrid electric vehicle as the investigation subject, this paper studies the remote data acquisition, supervisory control and redisplay system of the hybrid electric vehicle fault diagnosis. The system gathers the simulate CAN BUS data through serial ports by the data acquisition device and send data to the remote web servers by the GPRS wireless communication module. For the demands and features, the paper makes the module selection and design the hardware of lower computer ,and the software on the host computer and lower computer. It takes several notebooks as the simulate vehicle date emission source to make an experiment, achieving the function of wireless data transfer, data acquisition, supervisory, redisplay for multi hybrid electric vehicles at the same time, and protocol setting up. Especially the function of wireless data transfer and protocol setting up, make a big progress on the common use and convenience of fault diagnosis system.     

Study and Design on Teaching Experiment Instrument of CT Data Acquisition System Based on CPLD

The purpose of developing Teaching Experiment Instrument of CT is to demonstrate the whole process of CT scanning more intuitively, thereinto the design of data acquisition system is one of the emphases in the developing of the CT system. This paper mainly introduces the design and implement of the data acquisition system of CD - 50BG, using CPLD apparatus which have the characteristic of high integration, in the design of data acquisition system to achieve the target of minishing system bulk and improving system reliability. Aiming at the data loss of CD - 50BG during acquiring data, the data acquisition system is reformatively redesigned, the data loss in the high speed data acquisition process is reduced so that the stability of transmission has been improved by using FIFO.