基于感应励磁的混合励磁同步发电机性能

针对感应励磁发电机结构简单但励磁容量有限,永磁同步发电机磁场难以调节的问题,研究了一种将二者励磁功能相结合的混和励磁发电机。气隙中大部分磁场由转子上的永磁体提供,当需要调磁时,通过定子直流绕组与转子上感应绕组的感应作用,在感应绕组上获得调节磁动势,实现发电机磁场的调节。转子上两种励磁源为并联关系,调磁磁路磁阻小,无电刷-集电环系统,保证了发电机的结构简单、可靠性。在原理分析的基础上,使用二维有限元法对电机的磁场调节能力和负载特性进行分析,并进行了样机实验。有限元分析与实验结果都表明,与同结构参数的永磁同步发电机相比,混合励磁同步发电机具有灵活磁场调节能力;而相对于同一定子励磁磁动势的感应励磁发电机,该发电机输出容量大幅度提高,克服了感应励磁不适用于大容量发电的问题。

Performance of a Hybrid Excitation Synchronous Generator Based on Induced-Excitation

In view of simple structure but limited excitation capacity of induced-excitation synchronous generator and some difficulties in magnetic field regulation of permanent magnet synchronous generator, a novel hybrid excitation synchronous generator is analyzed in this paper. The current in rotor winding is produced by the double pole induction, which produce the magnetic field in the generator with permanent magnet. Thus adjusting the size of the stator exciting current, the regulation of air gap magnetic field could be realized. Due to removal of the slip-ring system, the machine reliability could be improved greatly. Based on principle analysis, two-dimensional finite element method (FEM) is used to obtain magnetic field adjusting and no-load as well as load characteristics. The simulation analysis results and those obtained in prototype tests both show that with the same structure parameters, the novel generator has more flexible magnetic field adjustment ability than permanent magnet synchronous generator. At the same time, the output of the hybrid excitation generator could be raise greatly than traditional induced-excitation synchronous generator.