The Research And Application Of Full Digital AC Speed Regulation Based On High Power Mine Fan

Mine ventilation system is the most important part of mine facilities, the ventilationperformance directly affects the underground air circulation, the safety of the gas emission,so the safety and reliability of its operation is very important. Because the design of themine fan is in accordance with the most chase air volume of the requirements for minemining, installed capacity of mine fan is very high. For the sake of security, design marginis large, so there is a large wind allowance at the beginning of the mine production and afterventilation system modification. Setting a damper baffle in the ventilation pipe andcontrolling baffle opening degree of the damper to control the size of the air volume is thetraditional way. The traditional control method, not only increases the air pressure, the fanload torque, and has a great waste of electricity.With the progress of modern agriculture and industry, for the sake of safety andreliability, the safety of the mine fan system operation has a higher request. Especially intoday’s energy conservation and emissions reduction environment, the demand to controlenergy saving and run efficiently is becoming higher and higher. In recent years, with thedevelopment of the modern ac motor speed controlling and Power electronic convertertechnology, it is becoming a necessity to modify the digital ac speed regulation for mine fanproject.Based on the mine fan operation features, this paper analyzes the fan tired load typewhich is belonged to the rate of2to the power load. then in combination with motor speedunder various air volume controlling of traditional fan, it is conclude that it is the mosteffective means of contemporary fan energy saving by ac speed regulating.For AC speed control scheme, the paper combined with traditional types of AC motorspeed control system, such as the lowering voltage control, electromagnetic slip clutch control, wound rotor induction motor cascade control, variable speed control of pole pairs,transformer frequency control, and as launching of new power electronic devices andmicroprocessor, the latest application of constant U/f control, vector control (VC) and directtorque control (DTC) of ac speed regulating system, it analyzed the advantages anddisadvantages of various speed regulation control scheme, determine the power of mill fanthis class2to the power load for AC speed regulation control method for constant U/fcontrol and vector control (VC).When the fan operation request is not high and not at low speed, the runtime can useconstant U/f control in big loaded case. When the fan control dynamics is in good running,and when loading ability at low speed is strong, the closed-loop vector control is used. Inthis paper, there search and applications of power mine fan speed regulation with full digitalAC variable system, are carried on the detailed analysis and research mainly from the fiveaspects.1.According to the current application status and development trend of mine fan,analyzed the reason of the current mine fan operation in low efficiency and poor safety andreliability, combining with the development of modern AC speed regulation technology andpower electronic technology, and summarized the development direction of AC speedregulating system and the advantages of the optimal application of AC adjustable speedsystem2. Depending on the application status and technical requirements of Shandong,Horizon mine, carried on energy conservation principle and the principle of AC variablespeed analysis to determine the AC fan speed control scheme of mine.3. According to AC speed control scheme, and from the induction motor mathematicalmodel and the basic principles of coordinate transformation, studied its control principle,and determined the double-loop rotor field oriented vector control programs, byMATLAB/Simulink system simulation, verified stability of low speed load and fast speedresponse and reliability based on the rotor the double-loop-flux-oriented vector controlsystem.4. Starting from the control scheme of AC variable frequency speed control of minefan, took the selection of various hardware equipment to determine the rationality of complete sets of equipment, designed installation and control circuit to determine thefeasibility of program.5. Combining with frequency converter model, analyzed the structure and operationway. Researched on the working principle and parameter, according to the two control modefor mine fan parameter setting, and for debugging and running, and resolved some problemsin debugging, and determined the effect of the inverter control applications.Through comprehensive analys is of AC speed control principle and mine fanoperation condition, designed of full digital vector control AC speed control system basedon the analysis of principle. By using MATLAB/Simulink simulation system analysis,verified the excellent frequency control of motor speed control of motor speed, and brakingperformance, wide speed regulating performance, high efficiency, high power factor and theadvantages of energy saving effect.Illustrated the all-digital AC drive system has become one of world concern and focuson the development of technology the areas of high performance AC speed.AC frequencycontrol technology in energy-saving, in industrial production, in improving processes toimprove product quality and improve the environment, has a broad outlook on theadvancement of technology applications.