【目的】针对传统等齿槽宽比结构易导致气隙磁场谐波含量高、劣化感应电压波形的问题,本文设计了一种基于轴向磁通的定子径向变齿槽宽比(S-RVSWR)对转双转子同步发电机(CR-DRSG)。【方法】本文提出一种三相6槽分数槽集中绕组模块化定子,其齿宽保持恒定、槽宽随定子圆周半径线性增加的变齿槽宽比结构;定子两侧转子均为24槽分布式绕组,主导极对数分别为2对极与4对极,通过对双转子进行直流激励产生的磁场分别与定子主导极对数磁场进行耦合。利用磁动势-磁导模型和径向积分理论,推导了非工作次谐波磁通的积分抵消机理。通过三维有限元仿真与样机试验平台,对比分析了传统结构与新结构的电磁性能。【结果】仿真与试验结果表明,S-RVSWR结构能显著改善感应电压波形,使其更接近正弦波。相比传统等齿槽宽比结构,其空载相电压(5 Hz)的总谐波畸变率从24.31%下降至5.20%,其中5次、7次和11次谐波幅值显著降低。【结论】该结构利用定子径向几何非均匀性产生的积分抵消效应,有效抑制了感应电压中的低频谐波,验证了S-RVSWR设计的有效性。

[Objective] To address the issue of high harmonic content in the air-gap magnetic field and deteriorated induced voltage waveform caused by the traditional constant slot-tooth width ratio structure, this study designs an axial-flux counter-rotating dual-rotor synchronous generator (CR-DRSG) with a stator-radially variable slot-tooth width ratio (S-RVSWR). [Methods] A three-phase 6-slot fractional-slot concentrated winding modular stator was proposed, featuring a variable slot-tooth width ratio structure where the tooth width remained constant and the slot width increased linearly with the stator’s circumferential radius. Distributed-winding rotors with 24 slots were placed on both sides of the stator, with dominant pole pairs of 2 and 4, respectively. The magnetic fields generated by DC excitation of the dual rotors were coupled with the stator’s dominant pole pair fields. The integral cancellation mechanism of non-working harmonic fluxes was derived using the magnetomotive force-permeance model and radial integration theory. The electromagnetic performance of the traditional and new structures was compared and analyzed through three-dimensional finite element simulations and a prototype experiment platform. [Results] The simulation and experimental results demonstrated that the S-RVSWR structure significantly improved the induced voltage waveform, making it closer to a sine wave. Compared to the traditional constant slot-tooth width ratio structure, the total harmonic distortion of the no-load phase voltage (5 Hz) was reduced from 24.31% to 5.20%, with the amplitudes of the 5th, 7th, and 11th harmonics notably decreased. [Conclusion] The structure effectively suppresses low-frequency harmonics in the induced voltage by leveraging the integral cancellation effect generated by the stator’s radial geometric non-uniformity. And the effetiveness of the S-RVSWR design has been verified.

中国博士后科学基金面上项目(2017M621086)；江苏省配电网智能技术与装备协同创新中心开放基金项目(XTCX202405)