Load Sharing Characteristics Analysis And Control Of Shearer Motor-Mechanical Short Cutting Transmission System

A shearer is one of the key equipment of mechanized mining face,and is an important technical equipment for achieving efficiently intensive coal-mining,reducing the fatal accidents of coalmine and improving the working conditions of working face.As the core component of the shearer,the cutting part is mainly responsible for the transmission of cutting power.The traditional coal mining machine cutting part uses the long chain gear transmission structure form,while it can only be used for traction speed regulation,and the adaptability of the whole machine to the complex change of the coal seam structure is weak,which results in the heavy load impact on the transmission system of the cutting part.In order to solve the problems existing in the transmission system of the traditional shearer cutting unit,the "973" project of our research group has put forward a kind of electromechanical short cut transmission system whose power is transmitted to the cutting part through the motor and torque coupled gear train planetary gear train.For the new type of cutting drive system,this paper mainly focuses on these works:(1)Established the electromechanical coupling dynamic model of the transmission system of the cutting part.The gear transmission system is built by using lumped-parameter method with the planetary gear train is simplified as the transmission ratio and the moment of inertia.The motor is controlled by direct torque control(DTC)and the basic performance of motor component is simulated.(2)Analyzed the influence of the internal excitation and external excitation on the load sharing characteristics of the coupled gear train.Due to the combined influence of the internal and external excitation of the coupled gear train,the load sharing characteristics of the coupled gear trains become worse.The external excitation of the motor output speed has greater influence on the load sharing characteristics,and the degree of synchronization of the output speed has greater influence on the load sharing characteristics than the degree of synchronization of the output torque.(3)The control strategy of load sharing characteristics of coupled gear trains based on speed synchronization is proposed.The relationship between the rotational speed of the three motors is established by the feedback of the output speed of the coupling gear train and the sliding mode compensation controller is used to compensate the torque of the direct torque control unit,so that the speed of each motor is synchronized with the reference speed of the torque coupled gear train.The simulation results show the effectiveness of the proposed control strategy for improving the load sharing characteristics of coupled gear train.(4)The drum load model is established,and the effect of the load variation of the drum on the load characteristics of the coupled gear train and the motor system is analyzed.It is shown that the motor current can reflect the external load and the running state of the motor.The load sharing characteristics of the coupled gear train under two typical speed regulation strategies is analyzed.Considering the load sharing characteristics and the coal productivity,a combined speed regulation control strategy is developed,and the effects of the three speed control strategies on the load sharing performance of the coupled gear trains and the coal mining productivity are analyzed.