| In the flywheel energy storage system,the classical PID controller of active magnetic bearing has the following problems in practical application: 1.It is difficult to find proper PID parameters efficiently by trial and error method 2.When the rotor starts to suspend and rotates at low speed,it will vibrate violently and even collide with the protective bearing.3.The amplitude of steady suspension is too large and it is difficult to recover when disturbed.This paper analyzes the influence of power amplifier on the control system of electromagnetic bearing control system,puts forward the serial PID control,and designs the Phase-Lead compensator,which optimizes the above problems to some extent.This paper introduces the principle of differential control of electromagnetic bearing,deduces the dynamic formula,and establishes the mechanical model of differential control.Then the classical PID control structure is briefly introduced,and the limitations of the classical PID control applied to the 600 WH flywheel energy storage device are analyzed,including simplifying the power amplifier into a proportional link and the deviation caused by the linearization of parameters.At the same time,the power amplifier is further analyzed,the mathematical model of each link of the power amplifier is established,the equation relationship between input and output is deduced,and the transfer function model of the power amplifier is established.According to the transfer function model of the power amplifier,the influence of the power amplifier on the gain and stability area of the control system is analyzed by using the root trajectory diagram,at the same time,the phase hysteresis of the power amplifier to the control system is analyzed by the Bode diagram.Aiming at the non-ideal root trajectory diagram,a series incomplete differential PID control is proposed,and the relevant parameters of the controller are determined via the Routh stability criterion and the requirements of equivalent stiffness and equivalent damping,thus the root trajectory of the system is significantly improved.When it comes to the phase hysteresis of the power amplifier,the Phase-Lead compensator is designed,the relevant parameters are determined,and the system Bode diagram is improved.After completing the design and optimization of the controller,MATLAB and SIMUILINK were used to pre-set the parameters of the control system,and then the response of the control system was simulated and analyzed.Then the source of the interference signal in the actual situation is analyzed,and the interference signal is added for simulation,which simulates the actual situation more truly and carries out simulation analysis.Finally,the experimental process of the whole control system and the establishment of the experimental platform are introduced.This paper introduces the software and hardware structure of the data acquisition system,the controller circuit structure,and the complete power amplifier principle circuit diagram.The basic principle board used for static balance position positioning of flywheel rotor and setting standard voltage,complete circuit diagram and balance position calibration method of conditioning are introduced.The new PWM circuit diagram,the principle and method of adjusting the high and low voltage of the opposite wave separately compared with the traditional PWM circuit are presented.This paper introduces in detail the experiments including the effect verification of each control system component,including the calibration method and calibration results of the sensor.According to the characteristics of the sensor,the standard position calibration experiment of the flywheel rotor was designed,and the static suspension experiment and the determination experiment of control parameters were carried out to verify the working effect of the controller and conditioning board.Finally,the experimental data were obtained through the dynamic magnetic levitation experiment,and the feasibility and optimization effect of the control system were verified by comparing with the experimental data of the classical PID control. |
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