Linear motor-assisted hoisting system and control strategy for extra-large skip in kilometer-deep wells

In the kilometer-deep coal shaft, the application of extra-large skips in deep mines of 1 000 meters can effectively improve production efficiency, but with the continuous increase of skip volume and capacity, the traditional method of steel wire rope mine hoisting will be challenged and it will cause hoisting rope strength insufficient, the reduce of the service life and the reduce of the security. In view of the shortcomings of the traditional method of steel wire rope lifting method, this paper takes a thousand-meter-deep coal mine as the engineering background, and proposes a super-large skip-lifting scheme using a vertical permanent magnet linear motor assisted drive, which can lift the skip at the current maximum of 50 t.Firstly, the overall hoisting scheme, mine layout and selection, skip structure and incremental design, auxiliary hoist motor structure design involved in the auxiliary hoisting system were analyzed in turn; Secondly, a control strategy combining master-slave control and parallel control was described in detail, which can realize the cooperative drive of multiple motors to skip, and ensure the stable operation of the auxiliary hoisting system. Finally, the unit motor and multi-motor vector control simulation models of the vertical permanent magnet linear motor-assisted hoisting system were established by MATLAB/Simulink, and the changes of speed and thrust of the system under constant speed, sudden speed change and braking conditions were analyzed. The results show that the unit motor has the characteristics of quick response, stable change of thrust and speed, high running accuracy under the condition of constant speed and variable load; the multi-motor control model has accurate performance in speed and output thrust following under constant speed and mutation speed; when the system adopts the master-slave speed following control strategy, it is difficult to brake stably in time under the sudden situation, so the parallel synchronous control strategy should be adopted in the system braking; considering the complexity of the actual working conditions in the kilometer-deep mines, although the simulation model is simplified, the system has sufficient synchronization and control stability. The research results have important theoretical value and practical significance for the design and development of extra deep shaft hoisting system.