| The local fan,the core of the local ventilation system,its stability and efficiency directly determine the safety of the mining work and the production efficiency of the coal mine.At present,the relay protection technology of the local fan in China is not mature enough so that many shortcomings are exposed during the operation of the local fan,such as low intelligence,poor sensitivity,and slow protection action and so on.When the local fans break down,the protection device doesn't run in time which causes equipment damage,and that is very easy to cause gas accumulation,seriously threatening the life safety of underground workers;in addition,most of China's coal mines use the method of constant speed operation of local fan,through the adjustment of the opening of the wind shield.However this method cannot adjust the air volume timely according to the gas concentration in the tunnel,which is more likely to cause safety accidents that include gas accumulation and the phenomenon of invariable speed.Moreover,the ventilator works in the long-term constant speed with low efficiency and serious waste of electric energy.In view of the above problems,this paper is about a design of a kind of local fan intelligent control protector with the functions of comprehensive protection and optimization of local ventilation control technology.On the premise of ensuring the stable operation of the local fan,the working efficiency of the ventilator is improved and the ventilation safety of the driving face is guaranteed.In this paper,DSP processor is used to realize the comprehensive protection of local ventilator.After analyzing the common fault characteristics and protection algorithm of the fan,an integrated protection scheme of the fan with specific and perfect functions is designed by adopting additional dc detection,speed breaking,fixed time limit,inverse time limit and other protection methods.Besides,after analyzing the local ventilation theory,ventilation of tunneling roadway and equipment layout,combining with the working principle of draught fan,this paper determines the variable frequency speed adjustment technology as a method of local fan in air volume regulation.According to the time-varying,non-linear and hysteretic characteristics of gas concentration in excavation work,a gas concentration fuzzy controller is designed.The rate of deviation of gas concentration and deviation of gas concentration is selected as the input of the fuzzy controller,and the frequency of input power supply of the local fan is the output of the fuzzy controller,which optimizes the control strategy of the local fan.This article takes TMS320F28335 DSP as the core,designs the software and hardware of the intelligent control protector,and tests the fan protection function and intelligent air volume adjustment function of the intelligent control protector in the laboratory environment.The results show that the intelligent control protector of local vfan can accurately judge and deal with common problems such as leakage,over-voltage and under-voltage,and current fault,as well as apply fuzzy control to local fan system so that local fan is efficient and well-adapted.The intelligent control protector of local vfan Can achieve the desired protection function and the effect of intelligent air volume adjustment. |
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