Optimization Design And Simulation Of Structure Of Magnetic Flywheel Battery Applied To Microgrid

In the crisis of energy and environment, Microgrid can effectively alleviate the great pressure that traditional power industry is facing. However the energy loss which caused because of the time of using of electricity is always different from power generation and the instability of distributed generation can make a huge impact on microgird. So the energy storage device of microgrid should have large capacity and good speed of t charging and discharging. Because of many advantages of magnetic suspension flywheel battery(MSFB) which other batteries do not have, such as high energy storage density,no pollution, charging and discharging quickly and no number limits of charging and discharging, this new kind of battery is very suitable for microgrid storage. But comparing to other areas of application, microgrid requires more stable dynamic characteristics, higher energy density and lower system power consumption for MSFB. To achieve this goal, the structure of MSFB is researched and analyzed in this paper.Firstly, the Supporting system of MSFB is researched. The mathematical model of magnetic suspension bearing (MSB) is build to analyze the magnetic force, stiffness and damping characteristics of MSB.Secondly, the motion equations of typical magnetic flywheel rotor is derived to research the dynamic characteristics of the rotor, which is also analyzed by using SAMCEF ROTOR. Firstly, the modal frequency and modal vibration mode of free rotor are got. Then how much influence on rotor’s critical speed and modal caused by different supporting stiffness and span, number of bearing and the structure of rotor is analyzed carefully. Besides, the relationship between the transient response of rotor’s displacement and different acceleration during the process of acceleration is analyzed. The conclusion is helpful to the design of acceleration program.According to the results of previous research, a totally new kind of structure of MSFB is designed. The structure of flywheel is made full use of. There are just a radial hybrid magnetic bearing which adopts Halbach array for permanent magnets and a axial hybrid magnetic bearing in the supporting system. Of course, there is Optimization Design for the two magnetic bearings. The basis of structural design is the capacity which is reached 3.75KWh. And the comprehensive quality volume energy density of flywheel is our optimization goal. And because of the design successfully make the limit rotational speed is lower than the bending critical speed, the rotor works in rigidity condition at any time. In this way, the structure is more compact, and the volume and weight become more optimized, and the power consumption of system is lower, also the bending critical speed is increased significantly.At last, the bearings’related Magnetic properties and movement coupling are analyzed by using ANSOFT Maxwell to verify the rationality of the design of magnetic bearings. The critical speed and related modal of the designed rotor is analyzed by using SAMCEF ROTOR to verify the rationality of the design of the rotor’s structure and supporting system.