Research On Coordinated Control Of Electric-hydraulic Compound Braking System Of Coal Mining

When the shearer is working on the large dip angle working surface,in order to prevent the occurrence of a slipping accident,the shearer needs to perform parking brake when parking.With the application of the frequency conversion technology of the three-phase asynchronous motor in the speed regulation of the shearer traction motor,if the shearer needs to stop in the horizontal working face,the feedback braking of the traction motor variable frequency speed regulation system is used to stop the brake.When the shearer stops in the inclined working face,the feedback braking of the traction motor will lose its function after the stop,and if the parking brake is not carried out,the skimming will occur,in order to prevent the shearer from walking in the inclined working face.A hydraulic brake is installed on the shaft of the shearer traction motor for the parking brake of the shearer.The working condition of shearer in inclined working face is divided into two types: braking and starting.The braking condition of shearer is divided into stopping braking when climbing and stopping braking when downhill,and the start-up of shearer is divided into climbing start and downhill start.In order to effectively coordinate the braking and start-up of shearer under different working conditions,this paper puts forward a braking scheme of shearer with electric-hydraulic compound braking.The braking force of the left and right traction motors and the braking forces of the motor braking and hydraulic braking are effectively distributed by means of the fixed distribution of braking force.Coal mining electric-hydraulic composite braking system can use traction motor to feedback braking to maximize the recovery of energy in the braking process.At the same time,the matching degree between electric-hydraulic braking system and hydraulic braking system can be improved,and the wear of hydraulic brake can be reduced as much as possible,so as to improve the reliability of hydraulic braking system of coal mining machine.In this paper,the electric-hydraulic compound braking system of coalmining on the face with large inclination is taken as the research object.Firstly,taking the 1940 type shearer as an example,the structure and working principle of the haulage part of the shearer are analyzed in detail.Secondly,the braking moment of the shearer is analyzed and calculated,which lays a foundation for the braking force distribution of the hydraulic braking system in the electric-hydraulic composite braking system of coal mining.Thirdly,the traction force of the shearer is analyzed and calculated,which provides the basis for the braking power distribution of the motor feedback braking system in the electric-hydraulic composite braking system of coal mining.Finally,based on Simulink and AMESim,the variable frequency speed regulation system of shearer and the hydraulic braking system of shearer are verified and analyzed by simulation.Through the improvement of the original quantitative pump hydraulic system,the original hydraulic braking system is upgraded to a variable pump load sensitive hydraulic braking system.The analysis results show that:The response speed of the load sensitive hydraulic braking system is faster than that of the ordinary hydraulic braking system(quantitative pump hydraulic system),so the matching degree between the motor braking system and the hydraulic braking system is improved effectively.In this paper,the fixed distribution ratio of braking force between left and right traction motor shafts is adopted in the distribution of braking power of coal mining electric-hydraulic compound braking system.And fixed distribution ratio of braking force between motor braking system and hydraulic braking system of coal miner.And the particle swarm optimization algorithm is used to optimize the braking force distribution ratio of the coal mining electric-hydraulic compound braking system.Finally,the correctness of the simulation is verified by the experiment on the coal winning machine climbing test-bed.The working efficiency of the electric-hydraulic composite braking system of coal mining has been greatly improved.