| With the continuous improvement of the output and quality of rolled highstrength thin strip steel,the load borne by the rolling mill has also increased,causing frequent accidents in the main drive system.The problem of torsional vibration of rolling mill is particularly prominent.In recent years.For the suppression measures of rolling mill torsional vibration,it is difficult to achieve effective vibration suppression control by calculating the output torque signal of the rolling mill according to the motor current.Therefore,online real-time monitoring of the torque signal of the main drive system and introducing it into the vibration suppression control system becomes the key to solve this problem.At present,the domestic high-frequency induction power supply type torsional vibration telemetry system developed for on-line monitoring of rolling mill torsional vibration,in which the high-frequency induction power supply device requires the stationary power ring and the rotating receiving ring not only to be coaxially placed,but also to ensure a 7-10mm gap.Many shortcomings of on-site installation,calibration,debugging and maintenance inconvenience.Therefore,the power supply of the rolling mill torque online monitoring system is a bottleneck and problem that restricts its long-term online monitoring,which needs to be solved urgently.This subject proposes a new type of rolling mill torsional vibration telemetry system based on the characteristics of the rolling mill site installation environment.Aiming at the special application scenarios of the rolling mill torsional vibration telemetry system,we are committed to solving the problems of inconvenient installation,calibration,debugging,maintenance and unstable power supply of the traditional rolling mill torsion vibration telemetry system.The newly developed rolling mill torsional vibration telemetry system is applied to the main drive vibration suppression control of the rolling mill,and a vibration suppression measure based on active disturbance rejection control is proposed.The main research work of this paper are as follows:(1)Problems of the existing rolling mill torsional vibration telemetry systemDuring the operation of the existing rolling mill torsional vibration telemetry system,there are problems that the position deviation of the inner and outer rings causes the electromagnetic parameters of the coupling mechanism to change,and the resonance point of the system changes,and the installation,calibration,debugging,and maintenance are inconvenient.In view of the particularity of the application scenarios of rotating shaft equipment,and according to the characteristics of the on-site working environment of the rolling mill torsional vibration remote measurement system,a new type of coupling mechanism rolling mill torsional vibration remote measurement system is proposed.The form of the primary side multi-winding coil broadens the system tuning range.The magnetic field is bound between the primary and secondary coils,which enhances the magnetic field distribution between the coils and improves the coupling effect of the coils.The vertical placement of the primary and secondary coupling coils can solve a series of application problems of the traditional coaxial placement coupling mechanism,based on finite element simulation and experiments,it is verified that the new rolling mill torsional vibration telemetry system has better stability.(2)Research on Power Supply of Rotating Shaft Torsion Vibration Telemetering Systema.Aiming at the detuning problem caused by the electromagnetic parameter changes of the wireless power transfer system under the influence of ferromagnetic metal medium,and the power loss caused by the eddy current effect,based on the electromagnetic theory,establish the wireless power transmission electromagnetic coupling mathematics of the torsional vibration telemetry system of the rolling mill under the influence of ferromagnetic metal medium model,derive the analytical expressions of the key parameters of the system,and reveal the mechanism of ferromagnetic metal media's influence on the eddy current effect and electromagnetic parameters of the wireless power transmission system.This modeling method can not only reflect the electromagnetic coupling characteristics of the system,but also carry out the system specific parameter design and energy efficiency optimization control.b.In view of the problem that the system impedance changes affect the system transmission efficiency and power,according to the system circuit topology,the impedance characteristics of the system are analyzed,the impedance matching strategy is designed using the Smith chart,and the peripheral circuit parameters that meet the impedance matching conditions are calculated.In-depth analysis of the wireless power transmission characteristics of the coupling mechanism of the rolling mill torsional vibration telemetry system under the influence of ferromagnetic metal media,reveals its resonance mechanism and frequency splitting phenomenon generation mechanism,obtains the influence conditions of the system's maximum efficiency transmission,and proposes that it can accurately track the maximum transmission efficiency resonance.The secondary-side current phase frequency tracking strategy based on the frequency points solves the problem that the traditional tracking primary-side current is easy to track the split resonant frequency point and the system cannot work at the maximum transmission efficiency.c.In order to adapt to the application scenarios of the rolling mill torsional vibration telemetry system,the wireless power transmission system model under the influence of ferromagnetic metal medium is established,and the threedimensional model of the system is established through ANSOFT Maxwell simulation software,and the effect of ferromagnetic metal medium on the transmission characteristics of the system is analyzed according to the simulation results.According to the analysis results,a magnetic shielding measure to suppress the eddy current phenomenon is proposed,and simulation and experiments verify that the suppressing measure can significantly improve the adverse effects of the eddy current effect under the ferromagnetic metal medium.The experimental results show that the magnetic shielding measure can make the system eddy current loss effectively reduce by about 31%.d.Establish a wireless power transmission experimental platform to verify the feasibility of the system design scheme.The wireless power transmission scheme of the new rolling mill torsional vibration telemetry system is a set of wireless power supply schemes designed for the special working scenarios of the rolling mill torsional vibration telemetry system.The system design includes:electromagnetic coupling mechanism design,inverter power supply design,rectifier circuit design,frequency tracking control circuit design,impedance matching circuit design.Finally,the effectiveness of the system is proved through experiments.The experimental results show that magnetic shielding measures and frequency tracking control strategies can increase the overall transmission efficiency of the system under the influence of metal media by about 43%.(3)Build a signal transmission system for the torsional vibration telemetry systemThe torque signal needs to be transmitted from the rolling mill drive shaft to the ground main control unit in the form of wireless signal transmission when the torsional vibration telemetry system monitors the rolling mill main drive system.Therefore,the use of WIFI communication ensures the stable short-range transmission of the torque signal of the torque telemetry system.In order to reduce the system energy consumption,this article uses dual serial channel WIFI module to realize the wireless transmission of dual signals,which not only ensures the efficient transmission of the two signals without interference with each other,but also reduces the system power consumption to a minimum,thereby reducing the burden of wireless power supply.To realize the signal transmission function under WIFI communication.First,the WIFI module transmitter collects the secondary side frequency tracking output signal and the torque voltage signal on the drive shaft,and then transmits it to the WIFI module receiver in the WIFI wireless communication mode.Since both the PLL output and the transmission of strain gages are analog signals,the result needs to be sent to the MCU after ADC conversion processing,so as to realize the wireless transmission of the signal through the WIFI serial port module.After receiving the signal,the main control unit on the ground restores the torque signal,and then transmits it to the computer through the network for collection,display and analysis.(4)Development of Rolling Mill Torsional Vibration Suppression DeviceThe new telemetry system for torsional vibration of rolling mill is applied to the vibration suppression control of main drive of rolling mill and a vibration suppression measure based on active disturbance rejection control is proposed.Based on the theoretical research and the analysis of measured mill torque signal,the vibration energy of hot continuous rolling mill is mainly provided by the main drive motor,and the torque signal of the main drive system of rolling mill is introduced into the vibration suppression control system to suppress the torque fluctuation of the drive system of rolling mill and reduce the vibration.The effectiveness of the proposed damping measures is verified by simulation and experiment.which greatly alleviates the vibration phenomenon of the rolling mill,and has achieved obvious results.High-quality thin strip steel provides guarantee.This research provides a new wireless power supply solution for the rolling mill torsional vibration telemetry system,which solves the installation,calibration,and disassembly problems of the traditional rolling mill torsion vibration telemetry system,and prevents the position offset and loss of the primary and secondary coils caused by the rotating shaft.The actual torque signal is introduced into the damping control of the main drive system of rolling mill,and the damping effect of the main drive system of rolling mill is improved.It provides guarantee for monitoring and suppressing torsional vibration of main drive system of rolling mill. |
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