工矿自动化

Research of wired broadband information transmission of coal mine underground

SUN Ji-ping

2013, 39(1): 1-5.

<Abstract>(49) <PDF>(6)

Abstract:
The paper pointed out that realization of unattended operation of fixed workplace of coal mine underground and limited worker operation of fully mechanized mining face and fully mechanized caving face needs to establish control system of coal mine with remote control function, video monitoring system, mine-used scheduling and communication system, mobile communication system, etc. It proposed that information transmission system of mine should meet requirements of wide transmission bandwidth, wired transmission mode combined with wireless mode, strong anti-fault ability, long transmission distance, high reliability, standardization, perfect safety performance, etc. It proposed double-tree redundancy structures of double cables in two tunnels separately, double cables in a tunnel and single cable based on analying advantages and disadvantages of structures of wired transmission networks of coal mine underground including star, ring, tree and bus mode, and considered ideal wired transmission network of coal mine underground should be the double-tree redundancy structure of double cables in two tunnels separately and double cables in a tunnel. It also put forward a view that wired broadband information transmission of coal mine underground should use mine-used Ethernet based on passive optical network or active optical network, and proposed main performances and technique requirements of the two Ethernets.

Research of intelligent miner equipment system

LU Zheng

2013, 39(1): 6-9.

<Abstract>(34) <PDF>(4)

Abstract:
For problems existed in coal mine underground that persons cannot know environmental status entirely, safety inspector has no technical support equipment, managers cannot know safety status of underground production, and there is no mobile equipment of commanding information in emergency rescue, the paper proposed a whole design scheme of intelligent miner equipment system, and introduced functions and design requirements of main equipments in the system including multi environmental parameters collector, intelligent handheld terminal, intelligent master and wireless base station. It pointed out that key technologies and design difficulties are multi parameters sensing in underground environment, vital sign sensing of underground persons, wireless ad hoc network under disaster condition, information fusion of multi systems and power dissipation, volume and weight of equipments, and proposed corresponding solutions. Finally, it expounded application modes of the system in daily management, safety inspection and command of emergency rescue in coal mine.

A processing method for underground image of uneven illumination based on homomorphic filtering theory

LIU Yi, JIA Xu-fen, TIAN Zi-jia

2013, 39(1): 9-12.

<Abstract>(50) <PDF>(8)

Abstract:
Traditional homomorphic filtering function is based on high pass filler, and images processed by the function are dark. The paper analyzed image filtering result by traditional low pass filter at cut-off frequency radius of 5, and got a conclusion that illumination component mainly distributes in low-frequency range of 0~5 radius. It introduced a design scheme of novel homomorphic filter, and proposed a processing method for underground image of uneven illumination based on homomorphic filtering theory. The method uses traditional low pass filter to restrain low-frequency components and traditional high pass filter to strengthen high-frequency components, divides range of low-frequency components of underground images into two sections, and uses different processing methods in the two low-frequency sections, namely restraining low-frequency components in the range of restraining radius of low-frequency and making low-frequency components invariant which are between restraining radius of low-frequency and strengthening radius of high-frequency, so as to avoid restraining low-frequency component overly. The testing result showed that the method solves uneven illumination problem as well as avoids weakening overall illumination of underground images overly, which has good effect.

Research of determination method of upper limit value of gas mutation pre-warning

LU Jian-jun, QU Shi-jia

2013, 39(1): 13-16.

<Abstract>(45) <PDF>(5)

Abstract:
For problem that abnormal gas change below pre-set warning value cannot be found in time because existing safety monitoring and control systems of coal mine use overrun theory and take measured value by gas sensors as criterion, the paper proposed a pre-warning method for gas mutation below the pre-set limit value, and introduced two gas mutation pre-warning methods named static pre-warning and dynamic pre-warning. It did stratified sampling as well as distribution validation and fitting of static data and dynamic data of pre-warning basic data of gas mutation below the limit value according to probed gas data of N2202 working face of Yuwu Coal Mine, and got a conclusion that the basic data distribution of the static pre-warning and dynamic pre-warning is both in normal distribution. It also proposed a method to real-timely calculate upper limit value of the static pre-warning and dynamic pre-warning with hypothesis testing and interval estimation, which was verified by use of probed gas data of N2202 working face.

A software redundancy method for improving reliability of data storage of EEPROM

CHEN Jia-cai, LI Qing-zhao, CUI Huai-bing

2013, 39(1): 16-19.

<Abstract>(53) <PDF>(9)

Abstract:
For problems that data stored in EEPROM of embedded microcontroller system would loss or change because of interference, the paper analyzes causes of loss or damage of stored data in EEPROM, and proposed a software redundant method for improving reliability of data storage of EEPROM. The method uses partition storage and CRC checksum technology to reduce possibility of collapse of the whole data in a given time, which improves recovery ability of EEPROM after stored data was partly damaged. The application showed the method can effectively improve reliability of data storage of EEPROM.

Design of monitoring and control system for water bursting in floor of coal seam

LI Cai-ping, ZHANG Ying-mei, ZHANG Zhen-guo

2013, 39(1): 19-22.

<Abstract>(40) <PDF>(4)

Abstract:
In order to solve problems of existing water bursting prevention methods such as large difference between theoretical parameters and actual environmental parameters, poor advanced forecast and real-time performance and so on, the paper proposed a design scheme of monitoring and control system for water bursting in floor of coal seam based on video monitoring, and emphatically introduced image processing algorithm of the system taking a water bursting accident in a coal mine as an example. The system obtains boundary point coordinates of water bursting image by use of digital image processing technology including graying, image enhancement, binaryzation, image segmentation and edge feature extraction, does curve fitting processing for the boundary point coordinates to get water bursting area, and judges change trend of water bursting according to the difference of the water bursting area at different time. The test run showed that the system is reliable with clear video image and effective image processing algorithm and can timely warn when water bursting is abnormal.

Application of message middleware technology in coal mine communication system

LIU Peng

2013, 39(1): 23-26.

<Abstract>(54) <PDF>(5)

Abstract:
For problem that transmission data in TD-SCDMA communication system of coal mine easily loss or change influenced by environmental factor, the paper proposed a scheme of using message middleware technology in coal mine communication system, introduced four-layer architecture of the communication system, and described realization of the message middleware technology used in the coal mine communication system. The message middleware provides both synchronous and asynchronous connections between layers of the communication system, and achieves status that data does not loss, not change and not leak during transmission by use of ensuring information transmission technology, message parsing and filtering technology, exception handling technology and Hibernate technology. The testing result showed that the message middleware technology increases data processing speed of the coal mine communication system and reduces error rate of the data.

Application of Ajax technology in mine attendance system

XU Xi-liang, GU Jun, MA Ke-feng

2013, 39(1): 27-29.

<Abstract>(38) <PDF>(4)

Abstract:
In order to solve problems of long response time and poor user experience of traditional Web attendance system caused by using submit means for data exchange, the paper proposed a scheme of using Ajax technology to design mine attendance system, analyzed principle of Ajax technology, and introduced realization of mine attendance system based on Ajax technology. Ajax technology sends asynchronous request to server by use of XmlHttpEngineRequest object, then gets data from the server, and renews page by operating DOM through JavaScript, so as to avoid situation that users wait for delayed server response caused by submitting form. The application showed that the system has high inquiry efficiency, quick respond speed, correct data statistics and perfect user experience.

Use improved Newton method to calculate theoretical line loss of distribution network

WANG Xiao-ming, ZHANG Li, ZHI Yong, ZHOU Xi-chao, XU Tian-peng, MU Xing-xing

2013, 39(1): 30-33.

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

Abstract:
The paper introduced traditional calculation methods of theoretical line loss of distribution network, and pointed out that electricity quantity method and root-mean-square method would cause too small theoretical energy loss and too large management line loss because of insufficient consideration of change of load curve. For above problems, it put forward a calculation scheme for theoretical line loss of distribution network by use of improved Newton method, which does power flow calculation according to power records of 24 h of each substation in the whole distribution network, so as to obtain total line loss of the distribution network. It used electricity quantity method, root-mean-square method and the improved Newton method to calculate theoretical line loss of a 10 kV distribution network separately, and got a conclusion that results calculated by the improved Newton method are closer to statistical value than the other methods.

Discussion of structured platform and service platform of mine Internet of things

ZHANG Shen, ZHANG Tao

2013, 39(1): 34-38.

<Abstract>(62) <PDF>(6)

Abstract:
The paper analyzed main problems existed in integrated automation system of coal mine at present and proposed that goal of real-time control, precise management and scientific determination of physical mine would be achieved by use of mine Internet of things technology and its platform performance. It pointed out that three-layer architecture of mine Internet of things determines that mine Internet of things should naturally be an opening platform, which is divided into two parts namely structured platform and service platform. It proposed that the structured platform of mine Internet of things includes opening sensing platform, opening main transmission platform and opening basic application platform, and introduced the service platform of mine Internet of things according to actual request of coal mine including underlying service platform for distributed monitoring and control, public service platform for the third party, collaborative working platform of multi disciplines and cloud service platform. Finally it pointed out that the structured platform could ensure effective implement of the service platform, and the service platform is suitable for building a public platform for different mine disciplines to work cooperatively so as to form a new cooperative work model based on Internet of things, which is also benefit for integrating different services into mine Internet of things and promoting development of special services for mine safety production.

Idea of whole design of unmanned fully-mechanized coal mining face and its implementation method

FU Guo-jun, YANG Ming-liang, XU Tai-shan

2013, 39(1): 39-42.

<Abstract>(37) <PDF>(2)

Abstract:
Unmanned or lee-manned fully-mechanized coal mining face is a core topic about coal mine safety. A view was pointed out that automatic coal mining should be pondered on from the whole fully-mechanized system, and fully-mechanized equipments should be classified into production equipment, auxiliary equipment and control center of coal mining face, whose control requirements were proposed. The composition of the control center of coal mining face and main functions of each part were emphatically described. The composition, system structure and characteristics of unmanned fully-mechanized coal mining face were introduced. It was believed that the unmanned fully-mechanized coal mining face could realize four-level monitoring and three-level control.

Research of key technologies for explosion-proof coal ash content analyzer

WANG Wen-qing

2013, 39(1): 43-47.

<Abstract>(47) <PDF>(12)

Abstract:
For status that coal ash content analyzers cannot be used in coal mine underground at present, the paper proposed a whole design scheme of explosion-proof coal ash content analyzer, and pointed out that key technologies of the content analyzer are ray penetration window technology and intrinsically safe power supply technology based on change rate detection of current. It proposed technical requirements of ray penetration window based on research of ray attenuation characteristic of coal ash content analyzer, and a new method of choosing materials of ray extraction window through theoretical analysis and tests, which solves problem of large attenuation rate of γ ray with low energy through explosion-proof enclosure and ensures precision of the coal ash content analyzer. The paper also proposed the intrinsically safe power supply technology based on change rate detection of current on the basis of research of influence of load characteristics of intrinsically safe devices on performance of intrinsically safe power supply, which overcomes shortage of current delay of inductive load and improves reliability of the coal ash content analyzer. The application of the coal ash content analyzer in coal mine effectively reduces waste discharge.

Research of preventing override trip scheme of coal mine underground based on GOOSE

MA Xing-he, WANG Yong-sheng, YAN Bing-yao

2013, 39(1): 47-51.

<Abstract>(60) <PDF>(2)

Abstract:
In order to solve problem of frequent override trip in high-voltage distribution network of coal mine underground, the paper analyzed causes of override trip in underground high-voltage distribution network and problems of common solutions in application including electrical locking, centralized control of substation, digital substation and differential protection of optical fiber current. It introduced the superiority of GOOSE message transmission protocol based on IEC61850 standard for data exchange. On the basis, it proposed a preventing override trip scheme based on GOOSE, and described implementation process of the scheme taking an underground high-voltage power line as an example. In the scheme, lower switches only associated with their upper switches, the upper switches and the lower ones communicated longitudinally through GOOSE protocol, and switches with the same grade do not communicated to each other, so as to improve real-time and reliability performance of information transmission.

Design of vital sign sensor for coal miner

YE Jin-jiao, WEN Liang, WANG Hong-yao, MENG Qing-yong, WEI Feng

2013, 39(1): 52-54.

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

Abstract:
For current status of lag in on-line health monitoring technology of coal miner and unrealized on-line monitoring of physical status of coal miners, the paper introduced whole structure of a kind of personnel location and health monitoring system of coal miner. It focused on technology of health monitoring sensor of coal miner, and proposed design schemes of body temperature sensor, pulse sensor, attitude sensor of rescuer and integrated vital sign monitoring sensor. The study result is important for preventing potential medical emergency events in coal mine.

Analysis and comparison of common liquid level detecting equipments in flotation process

WANG Ying, ZHANG Ke

2013, 39(1): 55-58.

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

Abstract:
In order to solve selection problem of liquid level detecting equipment in flotation control process, basic structure, working principle and application in separation field of common liquid level detecting equipments in flotation process were analyzed and compared including buoyancy type level gauge, laser level gauge, static level gauge and ultrasonic level gauge from the perspective of actual use. The analysis comes to a conclusion that each detecting equipment has own advantages and disadvantages for differences of sensors performance, stability of attachment devices and measured medium, thus concrete situation in flotation process, maintenance situation, performance of detecting equipment and cost of installation and use should be involved in concerning of selection of level detecting equipment.

Research status and direction of wireless networked control system

CHEN Hui-ying, LI Zu-xi

2013, 39(1): 59-63.

<Abstract>(35) <PDF>(10)

Abstract:
The paper described main research content and present situation of wireless networked control system from the aspects of industrial application based on wireless sensor network theory, design of control method, design of scheduling strategy and communication protocol and co-design of control and scheduling. It also discussed research direction of wireless networked control system.

Research of environment monitoring platform of mine area based on M2M

ZHANG Kai-sheng, CHEN Ming-ze

2013, 39(1): 63-67.

<Abstract>(46) <PDF>(2)

Abstract:
In order to monitor environmental status of mine area effectively and avoid occurrence of safety accidents, the paper introduced a design scheme of environment monitoring platform of mine area based on M2M technology. The platform uses M2M technology to monitor temperature, humidity, gas volume fraction, soil pressure and other environmental data in mine area, which also realizes function of personnel location by use of RSSI algorithm, and adopts least square method to do curve fitting for monitored environmental data for real-time display on monitoring interface of upper computer. The experimental result showed that the platform goes well with normal communication, and the monitored data curve after fitting processing is more smooth, which reduces data error greatly.

Simulation of PID control of jig discharging system optimized by genetic algorithm

LV Ting-ting, MA Xiao-ping, CHEN Li

2013, 39(1): 67-70.

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

Abstract:
In order to sovle problem of difficulty to obtain optimal control parameters and poor control effect of jig discharging system by use of traditional PID control method, the paper proposed a method of using genetic algorithm to optimize PID control parameters, and introduced PID control structure based on genetic algorithm and parameter optimization method and steps. It also simulated control performance of PID controller based on the method taking jig discharging system of a coal mine as an example. The result showed that the method can online optimize PID control parameters with quick convergence rate and strong robustness, and the PID controller has good static and dynamic performance, high control precision and no overshoot.

An improved ip-iq harmonic detection method

GONG Mao-fa, ZHANG Xu, ZHU Yi-kai

2013, 39(1): 70-74.

<Abstract>(33) <PDF>(2)

Abstract:
The paper introduced basic theory of ip-iq method based on instantaneous reactive power theory, and pointed out that there is error of amplitude and phase of active current component of fundamental wave detected by traditional ip-iq method because of phase difference between power grid voltage and its positive-sequence component. It proposed an improved ip-iq harmonic detection method. The improved method acquires synchronous rotation signal through combining positive-sequence voltage components with phase shift operator, which reduces detection error caused by three-phase voltage asymmetry, and introduces current mean value theory to replace low-pass filter, so as to improve dynamic response capability of harmonic detection. The Matlab simulation results showed the improved method can detect positive-sequence active current of fundamental wave correctly under condition of three-phase voltage asymmetry and has good dynamic response performance.

Reactive compensation scheme of three phase unbalance based on AC chopper device

CHENG Shun-zu, GUO Xi-jin, LI Su-ying

2013, 39(1): 74-77.

<Abstract>(46) <PDF>(3)

Abstract:
The paper proposed a scheme of using AC chopper device to compensate three phase unbalanced system dynamically and gave the device structure. The simulation result verified that the AC chopper device can adjust output voltage by changing duty ratio, and then adjust capacity value of capacitive load, which achieves dynamic reactive power regulation of unbalanced load. It also simulated application of the AC chopper device in reactive power compensation of three-phase four-wire unbalanced system by use of Matlab software, and the result showed that the AC chopper device can continuously and adjustably compensate unbalance current and pours no harmonic current into power grid.

Application of MPPT algorithm and input-output feedback linearization control technology in photovoltaic power system

ZHANG Ming-guang, LI Peng-yuan, XIE Wen-jie, LI Peng-fei

2013, 39(1): 78-83.

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

Abstract:
In order to solve problems of slow tracking speed and poor accuracy of the maximum power point tracking technology such as fixed voltage method, incremental conductance method and so on used in photovoltaic power system at present, a variable step size incremental conductance algorithm was proposed. For controlling grid current and DC bus voltage of photovoltaic power system, a new method was design by use of input output feedback linearization control technology, which allows control of both power factor and DC bus voltage using the same control algorithm. The model of photovoltaic power system was established and simulated based on the variable step size incremental conductance algorithm and input-output feedback linearization control technology in Matlab/Simulink, and the results showed that using the input-output feedback linearization control technology to control inverter makes changes of solar irradiation and temperature do not affect power factor of power grid, and the variable step size incremental conductance improves dynamic and static performances of the photovoltaic power system and reduces the total harmonic distortion of current in the power grid.

Research of deadbeat control of three-level paralleling active power filter

SHI Li-ping, WANG Jing-bo, ZHU Ning-tan, ZHAI Fu-jun

2013, 39(1): 83-87.

<Abstract>(48) <PDF>(2)

Abstract:
Working principle of three-level paralleling active power filter based on switching function was introduced, mathematical model for the active power filter was established, and a deadbeat control scheme for the active power filter was proposed. In the scheme, ip-iq method is used to detect harmonic current, reference current at the next sampling time is forecasted by use of load current detected at current sampling time and compensated current, and output reference voltage of the active power filter at the next sampling time is calculated. Finally, switch signal of bridge is obtained by use of space voltage vector algorithm to track and control current. The simulation result showed that the three-level paralleling active power filter controlled by the scheme can track and control detected current perfectly, which restrains harmonic effectively and has good dynamic response.

Analysis and calculation of heat dissipation of explosive-proof three-level converter with high power

WANG Chang-nan, HE Feng-you, TIAN Ming

2013, 39(1): 88-91.

<Abstract>(36) <PDF>(6)

Abstract:
For problem that a great deal of power loss of explosive-proof three-level converter with high power causes temperature rise and further affects converter performance, the paper analyzed principle, advantages and disadvantages of normal heat dissipation modes of electronic devices, and pointed out that the method using heat pipe combined with forced cold air is fit for heat dissipation of explosive-proof three-level converter with high power of coal mine underground. It also analyzed loss and temperature rise of main power devices of high power converter including IGBT, diode and fast-recovery diode under heat dissipation of heat pipe, and got formula of temperature rise of the power devices. The experimental result showed that error of calculated value according to the formula is in allowable range, which proves feasibility and correctness of the formula.

Data collection method of wireless sensor network based on mobile robots

WANG Fang, HU Yu

2013, 39(1): 91-95.

<Abstract>(63) <PDF>(3)

Abstract:
In sparse wireless sensor network, neighboring nodes are far away from each other. The requirement of direct communication among sensor nodes in traditional static data collection methods causes large time-delay and high energy consumption. In order to solve above problem, the paper proposed a data collection method of wireless sensor networks based on mobile robots. The method firstly takes a mobile robot as cluster head node which is nearest to a static sensor node, then judges node moving according to comparison result between average remainder energy of neighboring nodes detected by mobile robot in a period and average remainder energy of all nodes in the network. The mobile robot moves according to random moving strategy in controlled range. When the mobile robot arrives at a new position, the sensor node renews route and selects a new mobile robot as cluster head. The simulation results showed that the method can reduce time-delay of data transmission and energy consumption of sensor nodes greatly compared with traditional static data collection methods.

Research and probe on information management system of coal mine safety supervisio

HE Chao, SONG Xue-feng, LI Xian-gong

2013, 39(1): 96-99.

<Abstract>(46) <PDF>(2)

Abstract:
The paper analyzed research and application status of information management of coal mine safety supervision and pointed out that information management system of coal mine safety supervision is established on coal mine or mining group grade at present and safety supervision departments can only monitor simple data. It analyzed advantages of Internet of things applied in coal mine safety supervision, proposed an information management system of coal mine safety supervision based on Internet of things including two layers of provincial safety supervision and national safety supervision, and gave information structure of the system. It also discussed challenges of information standard, grading of safety factors, safety supervision hierarchy, content of information collection in the system implementation.

Probe on wireless voice communication system of coal mine based on ZigBee

XU Xiao-xiao, QU Guang-xiang, HUANG Yan-qiu, CAI Yuan

2013, 39(1): 99-102.

<Abstract>(66) <PDF>(2)

Abstract:
For problem that existing voice communication systems usually use wired communication mode, which cannot guarantee reliability of communication when an accident happens, a kind of wireless voice communication system based on ZigBee technology was proposed. The hardware and software design schemes of wireless voice communication node were described in detail. Reception rate and RSSI were tested under laboratory environment when terminal nodes were in different distances. The test result showed when communication distance between nodes is more than 60 m, packet loss rate is increasing, while RSSI decreases with increasing of distance between nodes. Thus distance between base stations is decided as 60 m, and coverage radius of the base station is as 60 m.

Research of common faults of electrical equipments in coal mine and their troubleshooting solutions

WANG Shu-feng

2013, 39(1): 103-104.

<Abstract>(52) <PDF>(2)

Abstract:
The paper introduced recognition methods of common faults of electrical equipments in coal mine and troubleshooting solutions about power supply, control system of electrical equipment, protection system of elctrical equipment and vacuum contactor, and proposed some notes at the time of troubleshooting. Finally, it pointed out that coal mine should eliminate common faults according to occurrence probability, use information system to monitor electrical equipment and improve technique ability and professional quality of electrician.

Research of lightning protection gap of 35 kV power line of coal mine

DENG Jie-wen, REN Wen-bin, LIU Yuan, ZHANG Dong, YI Xiao-fei, LIAO Zhi-hua

2013, 39(1): 105-110.

<Abstract>(36) <PDF>(2)

Abstract:
In order to test lightning protection effect of protection gap for 35 kV power line, the paper simulated lightning invasion in 35 kV transformer taking 35 kV overhead line of a mine as model by use of ATP-EMPT electromagnetic transient analysis software, and compared over-voltage peak value at high-voltage side of transformer before and after installing the protection gap. The compare result showed that the protection gap can significantly reduce the peak value of lightning invasion wave at high-voltage side of the transformer after 35 kV power line is subjected to single-phase or three-phase lightning. The paper also analyzed lightning withstanding level and rate of lightning trip of 35 kV power line with lightning protection gap, whose conclusions are the lightning withstanding level reduces and rate of lightning trip rises, while the two parameters satisfy requirements of DL/T 620-1997. The application results showed that the lightning protection gap installed on 35 kV line of coal mine can effectively inhibit lightning from invading substation device, but should run with automatic reclosing device for higher reliability of line lightning protection.

Design of remote video monitoring system of underground tunneling face and its applicatio

LI Ping, ZHANG Sheng-wang, ZHANG Hui-zhu, SUN Jin-yong, PENG Qing-hu

2013, 39(1): 110-112.

<Abstract>(34) <PDF>(7)

Abstract:
In order to solve problem of personnel safety caused by manual operation mode of roadheader in underground tunneling face at present, a remote video monitoring system of underground tunneling face was designed based on wireless network transmission, and components, function and application of the system on 12113 tunneling face in Yunjialing Coal Mine were introduced. The application showed that the system can collect, analyze, process and transmit video data in environment with coal dust and voilent vibration with satisfactory operation, and transmitting distance of wireless video signals achieves 40 m in tunnel as well as video monitoring distance is 500~20 000 m. The system realizes remote visual monitoring of roadheader.

Design of an isolated F/I converter

YANG Peng, DING Ji-cun, ZHANG Lei

2013, 39(1): 113-115.

<Abstract>(57) <PDF>(2)

Abstract:
The paper proposed design scheme of an isolated F/I converter. The converter uses PIC16F1823 single chip microcomputer to collect frequency signal of 200~1 000 Hz and transmits the frequency signal through SPI protocol to MCP4911 DA conversion chip for F/V conversion, then IC AD694 converts the voltage signal into standard current signal of 4~20 mA. The industrial testing result showed that the precision of data collection of the converter achieves 0.5 level, error range is less than ±0.5%, working current is 26.8±0.2 mA in full range, and the lowest power consumption is 450 nW.

Centralized control system for winch of mine hoister

GAO Yu

2013, 39(1): 116-118.

<Abstract>(65) <PDF>(6)

Abstract:
For problems of relay control mode used in winch of mine hoister such as simple protection, larger workload and so on, the paper introduced a centralized control system for winch of mine hoister which takes PLC as control core, takes integrated protector of motor as main protection device, and takes touch screen as human-machine interface. The system realizes functions of independent operation, synchronous operation, independent stop and synchronous stop of four winches of 16 t and two winches of 10 t operators, multi-protection of winch motor, and real-time display of winch parameters, which improves reliability of safe operation of winch and reduces labor intensity of operators.

Modbus communication between Siemens PLC and Ingersoll Rand air compressor

MENG Bin, WANG Chuan-song, SUN Jin-yong, HUANG Qing-long, WEI Wei, CHENG Liang-feng

2013, 39(1): 118-120.

<Abstract>(43) <PDF>(5)

Abstract:
For problem that it is difficult to online monitor multi parameters of Ingersoll Rand air compressor because the air compressor has few hard contacts, the paper proposed structure and functions of a centralized control system of mine-used air compressor based on Modbus communication mode, and focused on realization of Modbus communication method between Siemens S7-300 PLC and the air compressor. The communication method is simple in hard configuration as well as clear in programming, and can real-timely collect a lot of working parameters of the air compressor without any other sensors. The operation result showed that the system runs normally with high reliability.

2013 Vol. 39, No. 1

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