Hardware Design And Algorithm Research Of Bearing-Supported Control System For Magnetic Bearing Flywheel Battery

Flywheel battery is a revolutionary way to store energy. Comparing with chemical battery, the flywheel battery has high energy density, environmental-friendly character, nowadays it has became a research hot-spot around the world. Magnetic bearing is a contact-free supporting technology, using it to replace the conventional bearings in flywheel battery, which can not only help the flywheel energy storage to reduce the energy loss, improve the energy efficiency, but also speed up the rotating speed of flywheel battery and increase the flywheel battery energy density. Magnetic bearings, according to their various working principles, can be divided into:active magnetic bearings, passive magnetic bearings and superconducting magnetic bearings. Passive magnetic bearings are cheap but not controllable. Superconducting magnetic bearings have large load capacity, but its structure is complex and it has huge control systems. Traditional five degrees of freedom active magnetic bearings are better controlled and also have large capacity, but its excessive use of electromagnet are resulting in great energy loss.This article proposes a novel structure of the active magnetic bearings to achieve the five degrees of freedom full suspension. It relies on three electromagnets and three sensors to complete the supporting control of the flywheel rotor disc,and employs the centripetal force of electromagnet to restrict radial swing. This support approach not only inherits the advantages of traditional five-DOF active magnetic bearings, such as large load capacity,good controllability but also has other benefits like greatly simplified structure and reduced energy consumption. This article firstly demonstrates the three magnetic-bearing structure, the layout of sensors and electromagnets, the solution process of air gap between the rotor disc and electromagnets. In this article, the dynamic equation of the rotor, the mathematical model of control system of magnetic suspended flywheel battery,and its transfer function are also brought forward.Furthermore, this article has done research on flywheel battery controller design of three points against magnetic bearing, including hardware design and control algorithm. In hardware design, this article describes the battery Magnetic bearing control circuit board design based on the three inputs and three output of TMS320F2812DSP. In the control algorithm, employing the simulation model of Simulink control system to build and design the traditional PID controller, neuron PID controller, fuzzy PID controller and PID controller integral separated.In the trial of magnetic bearing flywheel controlled, it is found that the three points supporting magnetic bearings can meet the requirements of the rotor disc to magnetic bearings. A study of the control algorithm and circuit structure also can pave the way for the future design of simpler, more precise control of the flywheel battery.