Design Of Monitoring And Control System For Electromagnetic Bearings Based On LabVIEW

As the energy problem is becoming more and more serious,people pay more attention to improve energy efficiency and reduce energy waste.Flywheel energy storage technology as a relatively new way of clean energy storage is becoming more of a concern by energy industry researchers.Flywheel energy storage system is a combination system,including the mechanical system and electronic control system,its performance depends on the performance of electronic control system.In this paper,the composition of the electromagnetic bearing control system is analyzed including the design of Electromagnetic Bearing、the selection of Displacement Sensor、LABVIEW monitoring system components and functions、controller composition and power amplifier components.Then the composition of the electromagnetic bearing control system is introduced;a single degree of freedom mathematical model is established and the variation law of electromagnetic force under differential control is analyzed;the five-degree-of-freedom mathematical model and the state equation model is analyzed,preparing for subsequent state space control.The model of the electromagnetic bearing control system is established,and then the PID control strategy is selected,the standard PID algorithm to improve,resulting in integral separation PID and incomplete PID control strategy,and the transfer function of each link is calculated.According to Louth criterion to find the scope of stability control parameters to simulate the control system.The influence of control parameters on equivalent stiffness and equivalent damping is analyzed.PID control strategy to optimize,because the traditional PID control of the linear range is very small,so by designing variable-parameter PID control strategy to improve control performance.And then start the design of LABVIEW monitoring system,Firstly,the principle and hardware of monitoring system are introduced,design based on LABVIEW software program.About data acquisition module,the influence of sampling frequency and data acquisition mode on the collection precision is analyzed,then design the control of the motor is designed including monitoring the input voltage,current and speed of the motor,controlling the start,stop and speed of the motor remotely.Speed module design includes design principles and sensor selection.Then the collection of the rotor displacementinformation is designed.The design includes the rotor displacement curve,amplitude frequency characteristic,phase frequency characteristic,power spectrum and axis trajectory.It is convenient for online real-time analysis of rotor motion.Then the data storage module,the file data is stored in TDMS file type,the saved the data accuracy are consistent with the sampling frequency.TDMS data extraction and analysis simulates online dynamic test results,analysis of dynamic performance of the rotor at different times,no longer need to convert the file to other formats and analysis and process with other software.The electromagnetic bearing control system debugging and operation.First of all,the calibration of the sensor and digital PID control parameter tuning.Through the sensor calibration experiment found that different materials on the eddy current sensor coil inductance and inductance have an impact,so this will impact the eddy current sensor output linearity and sensitivity.The main work of debugging is to carry out static suspension experiment,simulation and debugging of magnetic levitation system.Finally,the dynamic experiment of the system is carried out,the rotor dynamic analysis near the natural frequency of the rotor is analyzed according to the LABVIEW monitoring system.According to the final experimental results,it is proved that LABVIEW monitoring system can monitor the system dynamic experiment well and the rotor kinematics analysis.Variable parameter control strategy can be satisfied with the control effect.