Research On Pump Speed Control Hydraulic System Of Mine Roadway Drilling Rig

Mine roadway drilling rig is an important equipment to ensure the safety on coal mining which mainly used for gas extraction in large underground coal mining projects. It should have advanced technology, safe and reliable, effortless operation, process applicability, high work efficiency and so on. The performance of drilling rig affects the cycle of coal mining directly. Currently, load sensing hydraulic system is widely used in drilling rig which requires higher quality oil. But the environment underground is very poor and dusty. So the machine is easy to be breakdown. VVVF hydraulic system uses a combination of quantitative motor and variable frequency motor to provide power. The system removed variable displacement mechanism of the variable pump to reduce the system requirements for oil quality greatly. It can be more easily automated and intelligent by electrical control strategy.Based on the above background and the special advantage of variable frequency control hydraulic system in the underground environment, this paper takes4000-Nm drilling rig for example, to improve the design of its hydraulic system, to use Simulink and AMESim software to build the system model and to analyze the application results of VVVF hydraulic system in drilling rig. The main work is summarized as below:This paper describes the development of drilling rig and its working principle under different conditions and analyses different control methods and their advantages and disadvantages on drilling machine hydraulic system. Pointed out that the load sensing system and frequency control system are suitable for the development needs of the drilling rig, but frequency control system is more suitable for coal mine complex conditions.The composition of each institution on drilling rig is to be analyzed in the second chapter. And the design of hydraulic system is to be improved based on the certain tunnel drilling machine.The characteristics of the different modeling methods of hydraulic system are analyzed in the third chapter. The mathematical models of inverter, AC motor as well as hydraulic system are created. The results show that the control voltage of the inverter is directly influencing factors actuator dynamics systemFinally, Simulink and AMESim simulation software are used to build the system co-simulation model, and to analyze the dynamic performance of drilling rig in different conditions. Simulation results show VVVF controlled hydraulic pump system can fully meet the coal mine complex conditions required. The system can be able to react quickly to the step loading put-in to ensure the normal operation of the machine. At no-load condition, motor idling operation. System power changes depending on load changes that achieves the purpose of saving energy. Compared to the load-sensing system, VVVF hydraulic system is much easier to control, the fluid medium requirements are very low, the failure of the system is reduced and the work efficiency is improved.