%0 Journal Article %T Theoretical Vibration Analysis on 600£¿Wh Energy Storage Flywheel Rotor¡ªActive Magnetic Bearing System %A Jing-na Liu %A Zheng-yi Ren %A Shan-wei Wu %A Yin-long Tang %J International Journal of Rotating Machinery %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/512674 %X This paper shows a theoretical vibration analysis regarding the controller¡¯s parameters and the gyroscopic effect, based on a simplified rotordynamic model. Combined with 600£¿Wh energy storage flywheel rotor system mathematical model, the Campbell diagram of the rotor system was obtained by the calculation of the whirl frequency under different parameters of the controller in MATLAB to analyze the effect of the controller parameter on the whirl frequency and to limit the operating speed and acceleration or deceleration of the rotor. The result of the analysis can be used to set the support position of the rotor system, limit the ratio of transverse moment of inertia and the polar moment of inertia, and direct the flywheel prototype future design. The presented simplified rotordynamic model can also be applied to rotating machines. 1. Introduction Later in the 1970s, flywheel energy storage was proposed as a primary objective for electric vehicles and stationary power backup [1]. With the improvements in materials, magnetic bearing technology, and power electronics, flywheel energy storage technology has large developments. Compared with traditional battery energy storage system, flywheel energy storage system has many advantages such as higher energy storage density, higher specific power and power density, lower risk of overcharge or overdischarge, wide range of operation temperature, very long life cycle, and environmental friendliness [2]. Many problems appear as the development of flywheel energy storage, and one of them is the bearing. Besides, the active magnetic bearing (AMB) implies that bearing forces are actively controlled by means of electromagnets, a well-designed closed control loop, and other components such as position sensors and power amplifiers [3]. Therefore, the rotor of the AMB can be suspended to the predefined positions by the controlled electromagnetic forces without mechanical contact and friction between the magnetic bearing and the rotor [4]. Based on the noncontact and frictionless characteristics, the magnetic suspension of AMB offers many practical and promising advantages over conventional bearings such as longer life, lower rotating frictional losses, higher rotational speed, and elimination of the lubrication [5]. Hence, AMBs have been successfully and widely implemented in various high-performance applications including the rotating devices such as turbine engines [6], flywheel energy and storage devices [7], bearingless motor [8], and vacuum pump [9] and the nonrotating devices such as motion control stage [10], %U http://www.hindawi.com/journals/ijrm/2013/512674/