新型永磁体外置式直线振动发电机性能研究

设计了一种新型圆筒式直线振动发电机，采用永磁体外置式结构，绕组和铁心放置在内侧，利用永磁体的振动产生感应电动势，该型发电机可以为小型设备提供低压直流电源.基于常规永磁体内置式振动发电机尺寸，设计了一款永磁体外置式发电机样机，并采用二维有限元方法对其非线性无边界轴对称磁场进行了系统分析，得到了感应电动势的变化曲线.样机实验结果和有限元分析结果吻合良好，该型发电机与现有的永磁体内置式发电机相比，效率高，永磁体用量少，去磁效应小，电机性能稳定.当2种发电机均以1 m/s速度运行时，永磁体外置式直线振动发电机的空载感应电动势幅值比永磁体内置式发电机高0.6 V左右，效率提高了约1.64%.

Performance of novel linear reciprocating generator with external permanent magnet

A novel tubular linear reciprocating generator was proposed.In the generator,an annular permanent magnet was placed outside of the winding and core. With the vibrating of the permanent magnet,the electro-motive force(EMF) is generated in the winding,so the generator can apply low voltage direct circuit power for small devices.A prototype was designed based on the dimensions of an internal generator.Then the unboundary axisymmetrical electromagnetic field in the prototype was systematically analyzed based on 2D finite element method(FEM),and the EMF curves were obtained.The prototype experimental results were in agreement with that of FEM analysis.Compared with the internal permanent magnet generator,the proposed generator has high efficiency,small permanent magnet,low demagnetization and good stability.With two prototypes run at the same speed of 1 m/s,the EMF amplitude of the external generator was 0.6 V higher,and the efficiency had a rough increase of 1.64% than that of the internal generator.