Research On Fast Drive And Control Technology Of Mine Solenoid Pilot Valve

Electro-hydraulic control system of hydraulic support is the core of safe and efficient production in underground coal mining.In the hydraulic support electro-hydraulic control system,the solenoid pilot valve as the pilot stage of the main valve,is one of the key equipment.In order to realize the precise control of the hydraulic support,reduce the hydraulic impact in the process of action,and enrich the control function of the hydraulic support,the mine electro-hydraulic proportional valve arises at the historic moment.But as mine proportional valve the forerunner level of mine electromagnetic pilot valve dynamic response is slow,a single drive strategy,power loss of the larger problem,unable to meet the demand of mine pilot control of electro-hydraulic proportional valve,and high response of high-speed on-off valve because the safety conditions of coal mine power limitation,also cannot achieve its dynamic response.Aiming at this problem,this paper improves the dynamic response of the existing intrinsically safe solenoid pilot valve for mining from the perspective of driving strategy.Firstly,the research status of structure optimization,material application and control strategy for the dynamic characteristics of on-off valve at home and abroad is analyzed and summarized.Combined with the existing use background of mine solenoid pilot valve,the dynamic characteristics and power consumption of valve are improved from the perspective of control strategy.Combined with the theory of electromagnetic field,mathematical modeling is carried out for the electromechanical converter,and the influencing factors related to response time and power consumption are obtained.The simulation model of the solenoid was established based on Ansoft-Maxwell software,and the static magnetic field characteristics were obtained,which were imported into the electromagnet module of AMESim.The AMESim-Maxwell co-simulation model of the solenoid pilot valve for mining was established.The motion state of the solenoid valve was analyzed through simulation,and the opening current was 73.5m A,the closing current is 14 m A,the steady-state current is about 110 m A,the opening lag time is 21.1ms,the opening action time is 13.3ms,the closing lag time is 134.2ms,and the closing action time is 21.7ms.Secondly,in order to verify the correctness of the co-simulation model,an embedded pilot valve control system is designed.Based on the STM32F407 core chip,a communication serial port module,a power supply module,a power amplifier module and a PWM wave output module are developed in the lower computer.The upper computer designed the control serial port program and the acquisition program in the development environment of Lab VIEW,and carried out the dynamic characteristics test of the mine solenoid pilot valve by using the designed control system.The test results are basically consistent with the simulation results.Finally,the effective co-simulation models were used to simulate and analyze the dynamic characteristics of the solenoid pilot valve under the driving control strategy of bipolar voltage,high and low double voltage and three voltage,and the driving control strategy of maintaining the duty cycle with PWM wave.According to the multi-voltage control mode,by changing the magnitude and action time of the corresponding voltage in different control mode,the influence law of the voltage on the dynamic characteristics is studied,and the suitable voltage parameters for each stage are determined.According to the mode of maintaining duty cycle of PWM wave,the influence law of pulse frequency and duty cycle in the maintenance stage is studied.The advantages and disadvantages of different driving modes are compared.The research content in this paper has a certain reference value for the dynamic characteristic optimization of solenoid pilot valve used in mine.