| In recent years,with the development and application of automation and intelligence technology of fully mechanized mining equipment,the mining speed of coal mining face has been accelerated,but the low intelligence of underground personnel transportation equipment has restricted the improvement of fully mechanized mining rate.As an important part of equipment energy-savingnd coconsumption reducingrading,the upgrading of overhead passenger device driving technology has an important impact on the intelligence,energy-saving and consumption-reducing of equipment and safe service performance.The traditional overhead passenger device transmission system is mainly composed of asynchronous motor,multi-stage reducer,driving wheel,etc.Among them,the use of multi-stage reducer extends the drive chain of the transmission system.With the extension of transportation distance and the increase of power,gears,shafts and bearings are prone to failure after the continuous operation of the mine.Once the failure occurs,it not only threatens the personal safety of passengers,but also makes the subsequent maintenance difficult and delays the production progress.The high efficiency and high performance of the system can be ensured by using the high efficiency permanent magnet synchronous motor(PMSM)to directly drive the overhead passenger device.However,the direct drive structure of the PMSM requires the output torque of the motor to be larger,resulting in the larger motor volume and lower power density of the drive system.If the semi-direct drive transmission mode of ‘PMSM+semi-direct drive reducer’ is adopted at the head of the overhead passenger device,the output torque and working space requirements of the permanent magnet synchronous motor can be effectively reduced.However,the stability of the low-speed torque PMSM and gear system is the basis for the application of permanent magnet semi-direct drive transmission in overhead passenger devices.Compared with the traditional long-chain overhead passenger device transmission system,the reduction of the reduction ratio of the permanent magnet semi-direct drive transmission system leads to the reduction of the rotating speed of each component and the increase of the load.At the same time,it also makes the transmission gear and permanent magnet motor have complex dynamic characteristics,which also brings greater difficulties to the vector control of the system.In this thesis,supported by the key research and development program of Shandong Province,combined with the coupling characteristics between permanent magnet motor and gear drive system,theoretical modeling,numerical simulation analysis,experiment and other methods are adopted to deeply study the dynamic characteristics of permanent magnet semi-direct drive transmission system of overhead passenger device.The research work mainly includes:(1)Based on the comprehensive analysis of the structure of overhead passenger device transmission system,a permanent magnet semi-direct drive transmission system is proposed by effectively integrating permanent magnet motor and gear transmission system with small variable ratio.According to the coupling relationship between the mathematical model of permanent magnet motor and gear dynamics model,the mechanical-electromagnetic coupling dynamics model of permanent magnet drive system of overhead passenger device is constructed.The dynamic load excitation source of permanent magnet semi-direct drive system is studied,and the dynamic response of permanent magnet semi-direct drive system under various working conditions is simulated according to the Runge-Kutta method.(2)The modal characteristics of permanent magnet semi-direct drive transmission system of overhead passenger device are revealed,and the influences of transmission system parameters and variable load conditions on the inherent vibration characteristics of transmission system are analyzed.The dynamic response of the transmission system in stable operation is analyzed by comprehensive Campbell diagram and frequency sweep analysis,and the resonance position and dangerous components of the system are further defined.According to Hopf bifurcation theorem,the bifurcation type of motor rotor vibration is determined,and the influence of supercritical Hopf bifurcation caused by torsional damping of motor shaft on the torsional vibration of motor rotor is studied.By Hurwitz criterion,the influence of linear control gain and nonlinear gain of Washout filter on the bifurcation point and limit cycle amplitude of the system is analyzed.(3)Combining nonsingular terminal sliding mode controller and fractional sliding mode load observer,a compound sliding mode speed control strategy for permanent magnet semi-direct drive transmission system is proposed.Based on the terminal sliding mode control theory,a nonsingular terminal sliding mode speed controller is designed,and the Anti-reset Windup method is used to improve the control input saturation problem.Taking the load torque as the extended state variable,the fractionalorder sliding mode load observer is constructed by integrating fractional-order theory and sliding mode control theory.Taking the observation value of load disturbance as the compensation control input of speed loop sliding mode speed controller,the design of compound sliding mode speed controller for permanent magnet semi-direct drive transmission system is completed.Finally,according to the vector control schematic diagram of permanent magnet synchronous motor and the electromechanical coupling dynamic model of permanent magnet semi-direct drive transmission system,the simulation model is established and verified.(4)According to the actual working condition of permanent magnet semi-direct drive transmission system of overhead passenger device,according to the similarity principle and dimensional analysis method,a small-scale test bench of permanent magnet semi-direct drive transmission system composed of permanent magnet motor,coupling,torque sensor,three-phase acceleration sensor and dynamometer was built,and the performance test of the small-scale semi-direct drive transmission system test bench was completed.The variation characteristics of motor current of permanent magnet semi-direct drive transmission system are studied,and the experimental research on dynamic characteristics of transmission system under step load,sudden load and steady load conditions is carried out,which verifies the correctness of the research on motor vibration and gear dynamic characteristics of permanent magnet semi-direct drive transmission system of overhead passenger device.The load observation effect of the designed FOSMO on a small-scale experimental platform is analyzed,and the experimental verification of the effectiveness of the compound sliding mode speed control strategy(AWNTSMC+FOSMO)is carried out.This dissertation has 90 figures,7 tables and 145 references. |
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