Optimal Design And Digital Control Research On Three-Stator Three-Degree-of-Freedom Magnetic Bearing For A Flywheel Energy Storage System

Flywheel energy storage technology is a new type of energy storage technology with high research value and broad application prospects by using high-speed rotating flywheels to store mechanical energy and energy conversion through mechanical energy conversion devices.And it plays an important role in areas such as power peaking,uninterruptible power supply,new energy vehicles,and satellite attitude control.In order to reduce the friction loss of bearings under high-speed operation,magnetic bearings is used in flywheel energy storage systems to support devices,which not only eliminates mechanical losses,but also reduces work energy consumption and noise,and extends the service life of flywheel energy storage devices.A new type of flywheel energy storage support integrated with a bearingless motor and a three-degree-of-freedom magnetic bearing is proposed in this paper,which optimizes the axial space and simplifies the system structure.Besides,a novel three-stator three-degree-of-freedom magnetic bearing(TS-3DOF-MB)is designed for the traditional three-degree-of-freedom magnetic bearing with insufficient radial bearing capacity.Research is carried out around its structure scheme,mathematical model,parameter design,optimization,and experimental design.The main contents and work results are as follows:Firstly,the research background and working principle of the flywheel energy storage system are introduced,and the key technologies of the flywheel energy storage are analyzed.In addition,the application prospects of the flywheel energy storage support technology and the research status at home and abroad is described in detail,and the research purpose and significance of the subject are pointed out.Secondly,the topology of flywheel energy storage system is introduced.Several commonly used flywheel energy storage support system topologies are listed,and the advantages and disadvantages of several schemes are compared and analyzed.Based on this,the energy storage of the flywheel and new structure of TS-3DOF-MB is proposed.Besides,The structure and working principle of TS-3DOF-MB are introduced,and its mathematical model is deduced using the equivalent magnetic circuit method and the radial-axial levitation force calculation formula.Third,according to TS-3DOF-MB prototype design requirements,the structure parameters are initially designed.The traditional parameter design for most parameters is empirical value,so it is difficult to guarantee the design of the magnetic bearing levitation force performance to achieve the optimal defects.To solve the shortcoming,an optimization algorithm is proposed to optimize parameters based on LV-SVM and harmonic chorus search,and the results of the parameters are compared and analyzed before and after optimization.Finally,an experimental platform for TS-3DOF-MB is constructed,and its overall control structure,hardware circuit design,and software program design flow are introduced.The start of suspension,suspension and anti-interference experiments and anti-interference experiments are conducted and the test results are analyzed in detail.