Papers by Keyword: Fault

Abstract: Because the complexity and The diversity of the fault of large-scale power generation equipment system, it is difficult to carry out the analysis and evaluation for risk of equipment failure definitely and accurately. In the present analysis, most of them are complex function formulas, and not only is it difficult to understand, but also in poor operating in practice. At the same time, it is fail to be divided according to different faults of different devices In the issue of risk classification in the present study, so that the risk classification is not reasonable. This article is based on the research about equipment failure risk assessment, and by risk factors analysis to classify the risk of different failure for different devices. Maintenance mode selection is no longer based on the device but a combination of criticality analysis, and we can propose appropriate maintenance mode in the light of different fault of different equipment.

Abstract: Oriented matrix analysis (OMA) method of system reliability is discussed. OMA uses an oriented fault graph instead of traditional fault tree model. By defining the specially logic operation and calculating reachability matrix, the cut sets can be formed directly and the minimum cut sets can be derived easily. An example is proposed at last, which verifies the efficiency of the proposed method.

Abstract: Loose blasting technology is applied to the problem of fully mechanized coal face passing through fault. The paper gets safe and practical loose blasting parameters and blasting process, achieves no re-open-off cut for the fully mechanized coal face, reduces loss of coal pillars for faults and improves the coal recovery rate. At last, the goal of high yield, steady yield, and increasing yield for fully mechanized mining face is realized.

Abstract: This document introduces basic principles of transmission in underground rock of ground penetrating radar (GPR) . Then an in-depth analysis on key parameters affecting the detection has been done, and detection resolution of radar are researched. By the technology, exploration experiments on Karst,little faults in coal seam and concealed metal drill pipe have been carried out. The results show that ground penetrating radar technology is a fast, efficient and intuitive geophysical detection technology, which provides a reliable technical means of solving the detection with close range and high precision.

Abstract: This paper investigates multi-agent consensus problem with an active leader as well as external disturbances and some faults. The undirected networks with variable interconnection topology are taken into consideration. Distributed consensus control algorithm is proposed to analyze the disturbance rejection and fault sensitivity problem arising in the coordination control of multi-agent networks. With a proposed control scheme, we then present sufficient conditions under which all agents can reach consensus with the desired performance index. Finally, simulation results are provided to demonstrate the effectiveness of our theoretical results.

Abstract: Faults are the commonly encountered large geological discontinuities in hard rock masses, many severe open pit slope failures are found to be closely associated with the faults presence nearby. Open-pit slope takes shape gradually as a rock unloading process accompanied by geostress redistribution, especially in a slope containing a fault. The finite difference code (UDEC) was employed as the analytical method in this paper and coulomb slip model was utilized to describe the properties of fault provided by UDEC. Parametric analysis has identified both the fault dips and fault locations relative to the open pit slope to be really critical for the open pit slope stability. The relationship of crest displacements, safety factor varying with these fault parameters was established. The distribution of plastic zone and displacement was graphically presented and the mechanisms such effects were discussed. These results offer a guideline in support design for an open-pit slope containing a fault.

Abstract: This paper is about a kind of instrument which can detect the fault object by acoustic sensor detecting the object Surface acoustic signals, through the analysis of the acoustic signal of the intensity and frequency content, so determining the object if abnormal conditions occur. Design by using Piezoelectricity material as the sensing head, the signal processing circuit is based on SH79F32 microcontroller as the core, the single-chip microcomputer, integration with ADC, the analog signal from the sensor to convert them into digital signals, in the procedure, carries on processing to the signal frequency components, filter out low-frequency components, acoustic signal was finally measured on a screen display. including hardware design, production, processing, software programming, to obtain the acoustic fault detector, and to test its performance, results show successful.

Abstract: According to characteristics of the power grid in China, a framework of microgrid for distributed generations (DGs) integration is proposed. To ensure the reliability of power supply, the framework access distribution network by single-bus section. The DGs consist of photovoltaic (PV) system, wind power system and energy storage system. Based on the proposed framework and control strategy, the models of distributed generations were built in DIgSILENT/PowerFactory. According to the control strategy, three cases were analyzed: 1) the dynamic operating characteristics of the microgrid from grid-connected mode to isolated mode; 2) the dynamic operating characteristics of the microgrid with wind speed fluctuation disturbance in grid-connected mode and islanded mode; 3) the influence to microgrid operation in different fault types and locations. The simulation results show that the proposed framework of microgrid conforms to Chinas power grid feature and the control strategy can ensure safety and reliable operation under different situation.

Abstract: in the thesis we introduce fuzzy mathematic method into fault diagnosis of hydraulic pressure system, bring forward the fuzzy membership grade method which is based on the history data and expert preferential ordinal number, set up a mathematical model of fault diagnosis, and carry out the fuzzy diagnosis on hydraulic pressure system fault in computer. The example shows that this method is advantageous to accuracy and credibility of decision and is valid and viable in the application.

Abstract: Choosing the junction of Altun-Kunlun orogenic belt as the anatomical area of extracting complex texture and structure information from remote sensing images, make full use of multi-band remote sensing images to reflect the characteristics of the properties, to extract hidden information through image processing. Analyzing the structure elements by geological body, rock combination, linear and banded structure, penetrative and non-penetrative planar structure, folds, to carry out the surficial composition and structure research of the the junction of Altun-Kunlun orogenic belt, identifying different geological bodies, the fault zones, ductile shear zones, superimposed folds and different strain zones, the different types of foliation, clarifying the characteristics of multi-source remote sensing image from the angle of the image processing methods, proposing new remote sensing image extraction methods and recognition of structural information technology and new understanding of the regional geology.