AMB-Supported Flywheel Battery for Electric Tractors: Structure Design and Driving Method

Abstract

Active magnetic bearing (AMB) supported flywheel energy system, also called flywheel battery, is a mechanical battery storing kinetic energy in a rotating flywheel disk and has appealing features such as high specific power and energy, short time of charging/discharging, no pollution and long life span. In this paper, we apply AMB-supported flywheel battery as a new type of power battery to electric tractors, which absorbs wasted energy when the electric tractor brakes frequently and provide additional driving energy supplement when the electric tractor face an overload start, a sudden load mutations or field work resistance mutations. The structure design of the AMB-supported flywheel battery is introduced, including the axial/radial magnetic bearing, flywheel disk, the rotor and the motor. The driving method of the whole system is also analyzed. This design provides the reliability guarantee for the innovative application of the AMB-supported energy storage flywheel battery in electric tractors.