轴承自供能监测的径向电磁式能量俘获建模与实验研究

Modeling and Experimental Investigation of Radial Electromagnetic Energy Harvesting for Self-powered Bearing Condition Monitoring

无线网络和低功耗微电子技术的进步推动着设备健康监测技术的网联化和智能化发展.轴承作为旋转设备的关键部件,对国防、轨道交通、风电等重大装备的健康状态起到了非常重要的作用,实现轴承状态监测的微型化和自供能是装备智能化的重要技术基础.论文针对于轴承无线传感器网络的供能问题,提出了一种用于轴承自供能监测的径向电磁式旋转能量俘获建模方法,并通过引入环形Halbach永磁阵列增强了线圈中的磁场强度,提高了能量俘获系统的输出性能.基于磁荷理论和空间坐标变换给出了环形Halbach永磁阵列的径向磁场计算方法,进而利用电磁感应原理建立了电磁式旋转能量俘获系统的输出电压模型,仿真分析了不同参数对系统输出电压的影响.有限元仿真和不同转速下的实验结果验证了所建立模型预测输出电压的准确性,同时功率测试实验表明设计的俘能系统在1000 rpm转速下可实现81.2 mW的输出功率.

Recent developments of wireless sensors and low-power microelectronics make great contributions to intelligentization and network technology of health monitoring.As key components of rotating machinery,bearings play a significant role in keeping the healthy states of defense,railway and wind turbine equipments.Therefore,miniaturization and self-powered methods for bearing state monitoring are important technologies.This paper presents a radial electromagnetic rotating energy harvester for bearing condition monitoring to solve the power resource of wireless sensor node in the future,and then introduces the circular Halbach array to improve the magnetic field of coils for performance enhancement.Based on the magnetic charge theory and space coordinate transformation,the calculation method of radial magnetic field distribution for circular Halbach array is proposed.Then the model of output voltage of the proposed energy harvester is established by electromagnetic induction.Moreover,the effects of different parameters on output voltage are numerically investigated by the proposed theoretical model.Finally,the finite element simulation and experimental results under different speeds demonstrate the effectiveness of the proposed model and indicate that the proposed device can obtain the maximum output power of 81.2 mW at 1000 rpm.