储能飞轮永磁卸载设计及试验

Design and testing of a permanent magnetic bearing for an energy storage flywheel

为解决大功率立式高速储能飞轮下支承高负荷高损耗问题,采用在飞轮上端轴向永磁轴承卸载的技术方案。以尺寸最小、卸载力达到飞轮重力(1kN)的80%为目标,磁路估算与有限元精算相结合,设计了一种磁路漏磁微小的内外双永磁静环与合金钢导磁转环组合的新型轴向卸载磁轴承。磁轴承的转动部件使用合金钢导磁材料,可适应500r/s、200℃工况需要。建立了永磁轴承卸载力测试装置,测量结果与有限元计算结果相吻合,在工作间隙1.5mm时,磁轴承卸载力达860N,轴承径向刚度为3.07kN/m。该卸载方案在旋转试验中收效良好,280r/s升降速过程中下支承温升始终处于正常范围。

An upper permanent magnetic bearing （PMB） was designed for a high-power, high-speed vertical energy storage flywheel. The bearing supports 80% of the rotor mass （100 kg） in the axial direction while greatly reducing energy dissipation and mass loading on the opposite lower bearing, The bearing consists of a radial two PM-ring stator and a alloysteel magnetic-conducting rotor which allows the flywheel to work at 500 r/s at 200℃. Magnetic-circuit estimates and a finite element analysis were used to calculate the unloading force and to minimize the bearing size and magnetic leakage. Quasistatic force-gap calibration results agree well with FEA calculation. With a gap length of 1.5 mm, the bearing has an axial unloading force of 860 N with a radial stiffness of 3.07 kN/m. Spinning tests at 280 r/s verify that the lower bearing remains at normal temperatures during use.