工矿自动化

Application research of alarming method for abnormal data of coal mine gas

ZOU Zhe-qiang, QU Shi-jia

2013, 39(6): 1-5.

<Abstract>(47) <PDF>(5)

Abstract:
The paper detailedly analyzed problems of how to determine lag time of data between two sensors, effect of sensor error, accuracy rate of alarm in application of alarming method for abnormal data of coal mine gas based on three kinds of correlation models of difference between the maximum and the minimum, the minimum and correlation coefficient, and proposed that data curve comparison method should be used instead of distance anemometer algorithm to determine the lag time, meanwhile, found phenomenon that movement speed of gas air mass in roadway is lower than wind speed and gave preliminary explanation for the phenomenon. It proposed a method to use mathematical statistics method to eliminate effect of sensor error. Combined with field data, verification was conducted on accuracy rate of the three kinds of correlation models, and the result shows that the alarming method can be effectively applied in practice.

Realization of visualization multivariable prediction method for gas content based on grey system theory

HAO Tian-xuan, ZHANG Hai-bo

2013, 39(6): 6-9.

<Abstract>(57) <PDF>(6)

Abstract:
In view of problem of low reliability caused by single-factor gradient method for predicting gas content in coal mine, the paper proposed a method of visualization multivariable prediction for gas content based on grey system theory, and established overall framework of the prediction model, presented flow of grey modeling numerical algorithm realized by dynamic link database. It detailedly introduced realization process of the prediction method combined with real condition of a Mine as follows: obtaining original data of gas content from digital gas geologic map, setting up related parameters for modeling, establishing multivariable prediction model for gas content, choosing point or batch prediction for gas content prediction, analyzing error of prediction result and displaying the result with graphic information. The prediction method improves prediction efficiency and scientificity of decision making, provides an intuitive, convenient and efficient visualization prediction method for daily gas content prediction, management and decision making in coal mine.

Application of acoustic emission technology in monitoring of underground pressure

ZHANG Yang, LI Zhan-jin, LI Shi-bo, ZHANG Yan-bo, FU Zhen

2013, 39(6): 10-12.

<Abstract>(33) <PDF>(6)

Abstract:
Through uniaxial compression acoustic emission experiments to goaf surrounding rock sample of a Mine, acoustic emission parameter values such as energy rate and event rate were obtained when rock failure. According to these values, parameters of acoustic emission monitoring system were set. Through statistics for long-term operation result of the acoustic emission monitoring system, waveforms of various underground activities namely rock acoustic emission, drilling, blasting, artificial crushing of large ore, ore drawing and percussion and parameter range of all kinds of the waveforms were summarized. Instability criterion of the goaf with characteristics of the energy rate and event rate were determined, so as to provide a reliable basis for judgment of underground pressure disaster.

Application of Verabar flowmeter in pipeline gas flow metering of coal mine

TAN Fei

2013, 39(6): 13-16.

<Abstract>(41) <PDF>(4)

Abstract:
In view of problems of complex installation, low measurement accuracy and large permanent pressure loss of pipeline gas flowmeter of coal mine such as V-cone flowmeter, orifice flowmeter and ultrasonic flowmeter, an application of Verabar flowmeter based on differential pressure measuring principle in the pipeline gas flowmeter of coal mine was introduced. Measuring principle and performance features of the Verabar flowmeter were given, a viewpoint was pointed out that the Verabar flowmeter has the best performance of anti-blocking compared with the other averaging velocity tube flowmeters. The result of experimental and field tests show that the Verabar flowmeter has characteristics of accurate measuring, simple structure, low pressure loss and can be suitable for detection of the pipeline gas flow of coal mine.

Research of distributed fault diagnosis and protection system of motor based on Internet of Things

GAO Xiang-ming, CHEN Yong-chao

2013, 39(6): 17-21.

<Abstract>(55) <PDF>(3)

Abstract:
In view of problems that traditional motor protection device cannot realize early fault diagnosis and does not have networking function, the paper proposed a design scheme of distributed fault diagnosis and protection system of motor based on Internet of Things and support vector machine algorithm. Lower computer of the system uses symmetrical component method to decompose stator current of motor, judges fault type according to current component value to realize site protection of motor, and sends current data to embedded gateway by ZigBee technology, uploads it to upper computer through GPRS network. Upper computer extracts fault feature vector by wavelet packet decomposition, uses support vector machine to classify motor fault, so as to realize early fault diagnosis and prediction. The actual running results show that the system can diagnose motor fault accurately and implement comprehensive protection effectively.

Research of rapid discovery method of information features of coal mine safety monitoring

LIU Pan, CHU Yan-cheng, HUA Gang, YAN Zhan-fang

2013, 39(6): 22-25.

<Abstract>(47) <PDF>(4)

Abstract:
According to characteristics of historical data and monitoring parameters in coal mine safety monitoring system, a rapid discovery method of information features of coal mine monitoring was proposed. The method uses compression algorithm of historical data based on error band to analyze sample data, discovers and stores information fragment that contains important features, analyzes meaning of the information fragment, conducts subject extraction and correlation analysis, researches correlation analysis of gas sequence, so as to get information features of important data in the coal mine safety monitoring system. The method has certain reference for completing scientific management of coal mine, excavating information of multiple sensors and law of gas discharge of coal mine.

Application analysis of WCDMA wireless communication system in coal mine

ZHANG Xiao-guang, LI Jun

2013, 39(6): 25-28.

<Abstract>(40) <PDF>(7)

Abstract:
In view of requirements to wireless communication system of coal mine at present, the paper analyzed and compared characteristics of existing mine-used wireless communication systems, described advantages of WCDMA mine-used wireless communication system, and analyzed its key technologies, introduced network architecture and function characteristics of the system too. The application result shows that the system can meet communication needs of daily production management of coal mine.

Analysis of quasi-resonant flyback converter with intrinsic safety output

ZHOU Xue-feng

2013, 39(6): 29-31.

<Abstract>(31) <PDF>(4)

Abstract:
The paper analyzed influence of input voltage and load resistance on switching frequency, output ripple voltage and peak inductor current of quasi-resonant flyback converters in a given input voltage and load change range, summarized its change rule, and concluded minimum design value of inductance and output filter capacitor meeting with electrical requirements to make the maximum output short-circuit release the minimum energy.

Research of fast acquisition method for low bit rate spread spectrum signal of mine through-the-earth communicatio

GUO Yin-jing, WU Kai, ZHAO Yuan, LI Chun-qiu

2013, 39(6): 32-35.

<Abstract>(57) <PDF>(6)

Abstract:
For features of low frequency and low bit rate of elastic wave through-the-earth communication system, a time-division multiple channel segment sliding correlation acquisition method was proposed. The method receives arrived code element in segment, and uses time of receiving next segment code to deal with previous received code segment, namely 1 PN code period is divided into several channel time slots, each time slot carries out fast sliding correlation search between previous received PN sequence segment and local PN code of channel. The theoretical analysis result shows the time-division multiple channel segment sliding correlation acquisition method can get almost the same search speed with parallel acquisition when its hardware cost is the same to serial parallel search. The simulation result validates validity of the acquisition method.

Improved transmission path loss model of mine electromagnetic wave

PENG Xia

2013, 39(6): 36-39.

<Abstract>(70) <PDF>(4)

Abstract:
In view of problems that basic path loss model based on received signal strength indicator (RSSI) is established on visual range between sending node and receiving node and it is not conformed to transmission characteristics of mine electromagnetic wave, the paper proposed an improved transmission path loss model of mine electromagnetic wave. On basis of basic model only considers attenuation factor, the improved model adds coefficient of multipath parameter and employs the least square method to calculate the two parameters. The calculation and Matlab simulation results show that the value obtained by use of the improved model is closer to measured value and has less error, and received power and transmission attenuation decrease with increasing of node interval.

Design of ultra-low power consumption receiver for wireless sensor network

ZHANG Quan-sen, HAN Tao, HUANG You-rui

2013, 39(6): 39-44.

<Abstract>(42) <PDF>(3)

Abstract:
In view of problem of influence of power consumption of wireless receiver on lifecycle of wireless sensor network, BFSK super-regenerative receiver, namely a wireless receiver with ultra-low power consumption for wireless sensor network was designed based on OOK super-regenerative receiver. Structure and circuit design of the receiver were introduced. The super-regenerative receiver employs two channels of f1 and f2 to determine output if “0” or “1” based on reserving ultra-low power consumption of OOK, and greatly improves transmission rate. The testing results show that the sensitivity of 2.4 GHz receiver is -86 dB?m and the power consumption is only 215 μW when its transmission rate is 250 kbit/s.

Self-tuning fault-tolerant PID control for mine hoist based on BP neural network

GUO Xing-ge, WU Jiao-jiao, LIU Jing, SUN Li

2013, 39(6): 45-48.

<Abstract>(48) <PDF>(3)

Abstract:
In view of problem that traditional analysis method is difficult to obtain dynamic feature when mine hoist system happened fault, the paper proposed a self-tuning fault-tolerant PID control method for mine hoist based on BP neural network. The method employs neural network to predict system output value by learning and tracking dynamic features of the hoist system online, uses self-tuning neural network PID of self-adapt control to build fault-tolerant controller, so as to realize stable fault-tolerant control of the hoist system when fault happens. The simulation result shows that control method can track system fault state rapidly when a sudden fault happens, and adjust PID parameters online and restore system features in short time.

Application of fuzzy information fusion in fault diagnosis of belt conveyor

HU Wei, LI Ou

2013, 39(6): 48-51.

<Abstract>(38) <PDF>(2)

Abstract:
In view of problems of uncertainty and locality of information obtained by a single sensor in process of fault diagnosis of belt conveyor, the paper proposed a fault diagnosis method based on multi-sensor fuzzy information fusion. The method fuzzes information of belt conveyor obtained by temperature sensor, dust sensor and smoke sensor, fuses the information through synthetic operation and decision rule in fusion center, so as to get accurate estimation and judge of state of the belt conveyor. The experimental result shows that the method improves accuracy and reliability of the fault diagnosis of belt conveyor.

Research of active disturbance rejection controller of direct torque control system of permanent magnet synchronous motor based on parameter optimizatio

YANG Jie, HUANG Ku

2013, 39(6): 52-56.

<Abstract>(40) <PDF>(3)

Abstract:
In view of problems of big torque fluctuation and easy to be influenced by load change existed in direct torque control system of permanent magnet synchronous motor based on PI controller, the paper designed an active disturbance rejection controller based on speed loop to replace PI controller to improve performances of direct torque control system of permanent magnet synchronous motor. It used particle swarm optimizer algorithm to make optimization calculation for the parameters of the active disturbance rejection controller and improved adjustment performance of the controller. The simulation and experimental results show that the system based on the active disturbance rejection controller with parameters optimization has higher ability of anti-disturbance of load, faster response speed and good dynamic and static performance.

Improvement of space vector modulation strategy of two-stage matrix converter

DANG Cun-lu, ZHAO Peng-lin, DONG Rui-hong

2013, 39(6): 56-61.

<Abstract>(46) <PDF>(4)

Abstract:
In view of problems that space vector pulse width modulation strategy of two-stage matrix converter has high control complexity and cannot adjust input power factor of the two-stage matrix converter, a scheme of indirect space vector modulation strategy was proposed, which average DC voltage in PWM period is a constant value and so modification to modulation coefficient of the inverter is avoided, and which input power factor angle is adjustable. Then the modulation strategy was simplified by use of reference voltage and matrix converter, and so the reactive power and output voltage could be controlled more effectively. The simulation result verifies correctness and validity of the modulation strategy.

Combination method of selective harmonic control for cascaded H-bridge multilevel inverter

GE Guang-jun, WANG Xi, SUN Bing-hai

2013, 39(6): 62-66.

<Abstract>(37) <PDF>(4)

Abstract:
In view of problem of low frequency harmonic in step voltage waveform of output of cascaded H-bridge multilevel inverter, a combination method of selective harmonic control was proposed. On the basis of trapezium waveform modulation, the method uses combination method of equal area principle and harmonic injection, switching conduction angle for selective harmonic elimination can be easily obtained by simple calculation of trigonometry formula deduction and optimized, so as to realize harmonic suppression. Taking three-phase nine-level cascaded H-bridge inverter as an example, simulation and experiment were conducted, and the result shows feasibility and validity of the method.

Design and simulation of high-pass filter based on improved memristor

YANG Biao, PAN Lia

2013, 39(6): 66-69.

<Abstract>(25) <PDF>(2)

Abstract:
In view of problem that traditional memristor model cannot conform to resistance variation characteristics of the memristor of physical model proposed by HP laboratory, the paper proposed an improved memristor model with threshold voltage. The model can simulate "activation" of the memristor very well, and its characteristics conform to the ones of memristor physical model in HP laboratory. Based on the improved model, a high-pass filter circuit was designed and it can change resistance of the memristor by changing output signal of resistance control circuit of the memristor, so as to realize cut-off frequency adjustment of the filter. The SPICE simulation result shows correctness of the design.

A detection algorithm of voltage sag used in dynamic voltage restorer

TIAN Ming, WANG Chang-nan, HE Cheng

2013, 39(6): 70-73.

<Abstract>(47) <PDF>(2)

Abstract:
In view of contradiction between compensation rapidity and anti-interference performance existed in traditional detection algorithm of voltage sag of d-q detection algortihom and Hilbert detection algorithm, a new detection algorithm of voltage sag combined d-q detection algorithm with Hilbert detection algorithm was proposed, namely, voltage signal of grid side was sampled, and the signal passed through d-q detection unit to get harmonic compensation waveform at first, then the signal passed through Hilbert detection unit to get voltage amplitude compensation waveform after the third harmonic was filtered from the signal. The two kinds of compensation waveforms were made superposing to get the final compensation waveform at last. The simulation results show that the detection algorithm has better compensation effect on voltage sag with the third harmonic and has abilities of compensation rapidity and anti-interference.

Research of closed-loop voltage and speed regulation method based on six-pulse-wave AC/AC frequency converter

LI Gao-ju, DU Qing-na

2013, 39(6): 73-76.

<Abstract>(30) <PDF>(3)

Abstract:
In view of problem of bigger speed difference between frequency levels in high frequencies in speed regulation technology of six-pulse-wave AC/AC frequency converter, the paper proposed a closed-loop voltage and speed regulation method based on six-pulse-wave AC/AC frequency converter. The method sets many voltage levels between two high frequencies, and changes output voltage of AC/AC frequency converter to realize closed-loop step voltage and speed regulation of the AC/AC frequency converter. The simulation and experimental results show that the method can use memory space effectively, expands speed regulation range of the AC/AC frequency converter, and has good speed regulation effect.

Research of three-level active power filter based on fuzzy control

LIU Jian-hua, LIANG Hua-yang, SONG Zu-lei, TANG Quan, LI Hui-mi

2013, 39(6): 77-80.

<Abstract>(29) <PDF>(2)

Abstract:
The paper proposed a control scheme of three-level active power filter based on ip-iq harmonic current detection, fuzzy PI current control and space vector pulse width modulation. It established a mathematical model of the three-level active power filter, and introduced concrete realization of control method of DC-side voltage stabilization and neutral-point potential balancing of the three-level active power filter. The simulation and experimental results show that the three-level active power filter controlled by the scheme has good effect of harmonic compensation, and can stabilize DC-side voltage and capacitance neutral-point potential well.

Comparison of methods of maximum power point tracking of photovoltaic cells

HE Yong-hui, LI La

2013, 39(6): 81-84.

<Abstract>(28) <PDF>(2)

Abstract:
According to engineering mathematics model of solar photovoltaic cells, a simulation model of photovoltaic cells was established in Matlab, influences of changed light intensity and temperature on output characterstics of the photovoltaic cells were analyzed. In view of problem that it is difficult to get higher tracking accuracy and response speed by use of perturbation and observation method which applied fixed perturbation step, an improved perturbation and observation method based on variable step was proposed. Through simulating photovoltaic cells control system, simulation curves of the two methods of maximum power point tracking were compared. The simulation results show that the photovoltaic cells control system can track maximum power point more quickly and has better stability at maximum power point by use of the improved perturbation and observation method.

Modeling and simulation of HVDC-Light system based on DIgSILENT/PowerFactory

LIANG Ke-jing, GUO Jia-hu, LI Peng-peng

2013, 39(6): 85-90.

<Abstract>(68) <PDF>(7)

Abstract:
The paper introduced structure characteristics of HVDC-Light system, built model of HVDC-Light system based on power system simulation software DIgSILENT/PowerFactory, analyzed steady state mathematical model of voltage source converter based on synchronous d-q rotating coordinate system and control strategy of DC voltage, active power and reactive power, and simulated dynamic performance under condition of change of the DC voltage, active power and reactive power. The simulation results show that the system has good ability of dynamic response and robustness, can steady work between two power grids, and independently control reactive power to compensate static reactive power.

Research of temperature monitoring system for cable joint based on temperature field

HU Wan-qing, HU Qing-yi, LIN Xue, LIN Shan-ming

2013, 39(6): 90-93.

<Abstract>(54) <PDF>(3)

Abstract:
In view of problem that core temperature of cable joint cannot be measured directly, the paper applied finite element method to establish a model of steady temperature field distribution of cable joint, used ANSYS software to simulate and analyze the temperature field distribution, obtained the relationship between the core temperature and surface temperature of the cable joint. It proposed a design scheme of temperature monitoring system for cable joint based on temperature field according to simulation result, gave design of power supply and data processing of the system, so as to provide a theoretical basis for monitoring of joint temperature and running status of cable in engineering.

Research of material supermarket management system of coal enterprises based on Internet of Things

WANG Xiao-bin, LU Jian-jun, WEI Chen

2013, 39(6): 94-97.

<Abstract>(72) <PDF>(2)

Abstract:
In view of problems of too much residual inventory and high production cost in material supply management system of a Group Company, the paper proposed a design scheme of material supermarket management system of coal enterprise based on Internet of Things. It introduced key technologies of the system and actual business needs of material management of the Group Company, gave system structure based on perception layer, network layer and application layer, and introduced realization scheme of each layer in details. The system reflects effective utilization of Internet of Things in material management of coal enterprises.

Design of embedded Web network video monitoring system based on H.264

REN Zi-hui, LIU Wei, ZHU Hui, XU Sheng-long

2013, 39(6): 98-101.

<Abstract>(55) <PDF>(2)

Abstract:
For problem that traditional video compression technology is not suitable for application in bad network environment, the paper proposed a design scheme of remote video monitoring system based on H.264. The system combines embedded technology, network technology and video coding technology together, video signal collected by camera of the embedded system was transferred to remote monitoring terminal in real time through built-in Web server of the system after it was compressed according to H.264 standard code, so as to realize interconnection communication between browser of the remote monitoring terminal and embedded Web server. The test result shows that the system has high video compression ratio, clear image and strong real-time performance.

Analysis of installation, use, maintenance and management of underground personnel positioning system

MIAO Xue-fu

2013, 39(6): 101-105.

<Abstract>(64) <PDF>(4)

Abstract:
Taking construction of personnel positioning system of a Mining Group Company as an example, topology of the system was given, installation and notice in debugging of wellhead inspection card system, installation position requirements of underground substation and card readers were introduced in details, key points of ensuring reliable running of the system and accuracy of monitoring personnel information were also introduced in details. The paper has certain reference for how to establish, use, maintain and manage the underground personnel positioning system.

An improved voltage measuring method for single battery in series batteries

LIN Yin, DENG Fei, LIU Ya-hui

2013, 39(6): 106-108.

<Abstract>(66) <PDF>(3)

Abstract:
In view of problem of leakage current in voltage measuring method for single battery in series batteries based on operational amplifier and MOSFET, an improved voltage measuring method was proposed. Voltage follower is added at two ends of each battery to reduce leakage current effectively; photoelectric relay is added as power switch of operational amplifier to make voltage measuring circuit not consume current under status of power off; zener diode is added to prevent breakdown of MOSFET. The test result validates effectiveness of the improved method.

Improvement of three-proofing lacquer coating process for mine-used PCB assembly

DU Qing-jie, WANG Qiang, TANG Quan-hai, JIANG Zhi-long

2013, 39(6): 109-112.

<Abstract>(47) <PDF>(3)

Abstract:
In view of problems of low controllability and poor coating consistency of traditional three-proofing lacquer process affected by factors of technology and environment, an improved three-proofing lacquer coating process for mine-used PCB assembly was proposed. Selection of coating way and material of the three-proofing lacquer was described, method and content of the three-proofing lacquer coating process for mine-used PCB assembly were researched. The experiment result shows that the selection of two-component polyurethane paint and selective spraying method has good consistency of coating, and improves production efficiency.

2013 Vol. 39, No. 6

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