| Belt conveyor has always been an important facility in the process of coal mining transportation.In the downhole mine,the belt conveyor has the characteristics of long conveying distance,bad working environment and large workload.With the development of information technology,intelligent inspection robot has gradually replaced manual inspection and become the common means of inspection.However,there are many security risks in the traditional contact wired charging methods of inspection robot.For the sake of solving the charging problem for the intelligent inspection robot in the downhole,this dissertation studies the design of a wireless charging system in the downhole,which guarantees the battery life of the intelligent inspection robot,improves the charging efficiency of the inspection robot,and realizes the efficient work of the intelligent inspection robot.The main research contents of this paper are as follows:First,analysis of the current three mainstream radio transmission technology,the radio can transmit in all areas within the application status of inspection robot according to the design of the downhole charging demand,combined with the downhole work environment,overall design to the downhole wireless charging system,can determine the magnetic coupling resonant radio transmission technology for downhole wireless charging system technical support,illustrate the basic system.The system wireless communication function and the autonomous charging function of the inspection robot are designed.Second,the transmission characteristics of the downhole wireless charging system were studied theoretically and the magnetic coupling mechanism was determined to adopt series resonant structure.Two coil mode and S-S type compensation network,the equivalent circuit model of the system was established,the formula of output power and transmission efficiency of the system was deduced,the key parameters affecting the transmission efficiency of the system were analyzed,and the resonance frequency of the system was respectively studied by using Matlab simulation software.Through the comparison of genetic algorithm and particle swarm optimization algorithm,the improved adaptive particle swarm optimization algorithm was applied to the system parameter optimization,and a set of parameter optimal values were obtained,so as to improve the transmission efficiency of the system.Third,the magnetic coupling mechanism of the downhole wireless charging system was optimized.Ansys Maxwell electromagnetic simulation software was used to analyze and calculate the magnetic field distribution and coupling coefficient of the coil,and then the winding parameters such as the coil with planar double-disc structure and the coil's turn distance,radius and number of turns were determined.In this paper,the influence of coil offset on the transmission efficiency of the downhole wireless charging system was studied,and the coil offset was optimized by particle swarm optimization algorithm.An aluminum shell is designed for the magnetic coupling mechanism with a shielding device with a flat ferrite core.This device not only shields the electromagnetic interference,but also improves the transmission efficiency of the system.According to the optimized design of the magnetic coupling mechanism,the physical object of the magnetic coupling mechanism was made,and the related electrical parameters of the coil were tested to provide parameter basis for the later simulation and experiment.Fourth,the system circuit part and charging control strategy were designed,and the power was adjusted by adopting double-loop PID control of the BUCK conversion circuit.The simulation software Matlab/Simulink was used to establish the system model and analyze the simulation results,which proved the feasibility of the downhole wireless charging system.The whole prototype of the downhole wireless charging system was built,and the functional test experiment was carried out,which showed that the system circuit was running correctly,and the wireless charging function could be realized.The optimal working frequency test,the optimal transmission distance test,the coil offset test and the working frequency transmission distance analysis were conducted respectively.The influence of coil offset on the system transmission efficiency is verified to verify the correctness of the simulation,and the optimal transmission distance of the system operation is obtained as H=6cm,so as to achieve the goal of improving the charging efficiency of the inspection robot. |
PDF Full Text Request