【摘 要】
：
Underground Electro Magnetic Interference (EMI) has become so serious that there were false alarms in monitoring system, which induced troubles of coal mine safety in production. In order to overcome difficulties caused by the explosion-proof enclosure of
【机 构】
：
State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology Be
论文部分内容阅读
Underground Electro Magnetic Interference (EMI) has become so serious that there were false alarms in monitoring system, which induced troubles of coal mine safety in production. In order to overcome difficulties caused by the explosion-proof enclosure of the equipments and the limitation of multiple startup and stop in transient process during EMI measurement, a novel technique was proposed to measure underground EMI distribution indirectly and enhance Electromagnetic Campatibility(EMC) of the monitoring system. The wavelet time-frequency analysis was introduced to underground monitoring system. Therefore, the sources, the startup time, duration and waveform of EMI could be ascertained correctly based on running records of underground electric equipments. The electrical fast transient/burst (EFT/B) was studied to verify the validity of wavelet analysis.EMI filter was improved in accordance of the EMI distribution gotten from wavelet analysis.Power port immunity was developed obviously. In addition, the method of setting wavelet thresholds was amended based upon conventional thresholds in the wavelet filter design.Therefore the EFT/B of data port was restrained markedly with the wavelet filtering. Coordinative effect of EMI power and wavelet filter makes false alarms of monitoring system reduce evidently. It is concluded that wavelet analysis and the improved EMI filter have enhanced the EMC of monitoring system obviously.
其他文献
The configuration, function, principle of operation and the main design of the wireless remote measurement system of drill hydrology based on GPRS were introduced in this paper. The current resources of GPRS network was used by the system, and water level
By simplifying saturatedly magnetized wire-rope to magnetic dipoles of the same magnetic field strength, an equivalent magnetic dipoles model is developed and the measuring principle for recognising damage of broken wire was presented. The relevant calcul
A new nonsmooth equations model of constrained minimax problem was derived. The generalized Newton method was applied for solving this system of nonsmooth equations system. A new algorithm for solving constrained minimax problem was established. The local
The checking survey in Open mine is one of the most frequent and important work. It plays the role of forming a connecting link between open mine planning and production. Traditional checking method has such disadvantages as long time consumption,heavy wo
The traditional open pit mine slope deformation monitoring system can not use the monitoring information coming from many monitoring points at the same time,can only using the monitoring data coming from a key monitoring point, and that is to say it can o
In order to provide experimental guide to commercial use of fluorine pollution control during coal combustion, with fluorine pollution control during coal combustion in mind, this paper proposed the theory of combustion fluorine retention technology. Feas
MRCR could be regarded as a multi-stage compounding real option, based on option theory, assuming the convenience yield of coal reserves to be constant, built a one-factor model of valuating MRCR with the stochastic value of coal reserves. On the basis of
Outlined the South African mine health and safety regulatory framework, including the roles of government, tripartite council, service agencies, mine enterprises,rescue stations and workers unions, analyzed the institutional structures of South African mi
Function simulation, which is called virtual reality too, is popularly applied to solve uncertain problems. Good performance of hidden layers and perfect capability of function simulation make artificial neural networks one of the best choices to simulate
Aiming to the deficiency of safety management measure, established simulation model about firm\'s safety management capability(FSMC) based on organizational learning theory. The system dynamics(SD) method was used, in which level and rate system, variab