Research On Control Strategy Of Magnetic Flywheel Energy Storage Supporting System

The flywheel energy storage technology is a new type of mechanical energy storage technology, which has a larger number of advantages such as high energy conversion efficiency, store energy density, fast charging and discharging, long service life, more important is no waste gas waste pollution, in accordance with energy storage technology in the future development prospect. The role of the flywheel bearing system is very critical, which not only make the flywheel rotor reliable and stable running, as much as possible reduce the energy loss. Magnetic suspension bearing is a kind of non-contact supporting technology, used to replace the traditional bearing of flywheel energy storage, not only can reduce the energy consumption in the process of flywheel energy storage, improve the energy utilization, also can speed up the speed of the flywheel, increase the energy storage density.The thesis mainly explores the flywheel rotor bearing system research. Discusses the research status of the magnetic suspension bearing and magnetic suspension bearing system control method at home and abroad, has been clear about the significance of the magnetic suspension bearing technology used in flywheel energy storage system, established the research direction.In this thesis, hybrid magnetic bearings are used as the energy storage flywheel bearing system, which incorporates the comprehensive characteristics of active magnetic bearings and passive magnetic bearings, and selects the axial-radial direction hybrid magnetic suspension bearing and radial magnetic suspension bearing support structure. Introduces the axial–radial hybrid magnetic suspension bearing structure and their working principle, the magnetic bearings are analyzed by using equivalent magnetic circuit method, deduce the formula and mathematical model of axial-radial magnetic levitation force. And the coupling between axial and radial direction of magnetic bearings are analyzed, it is concluded that the axial and radial suspension force is decoupling near the rotor equilibrium position, which brought great convenience for the control.Finally, the control strategies of the maglev flywheel energy storage support system are studied. Hybrid magnetic suspension bearing system has nonlinearity and instability problems, the variable universe fuzzy PID control has been a lot of research, and its control effect is superior to the conventional PID and fuzzy PID control. The modified variable universe fuzzy PID control algorithm is designed for axial hybrid magnetic bearing system based on the traditional variable universe fuzzy PID control algorithm, the fuzzy controller output of output contraction-expansion factor are improved, which makes up for the faults that traditional variable universe fuzzy PID control algorithm cannot make the universe range of fuzzy PID controller outputs are respective variable. Simulation results show that in the magnetic suspension bearing system, the modified variable universe fuzzy PID control has good dynamic, static performance and strong anti-jamming capability.