双凸极无刷直流发电机的换相研究

Study on overlapping commutation in doubly salient brushless DC generator

双凸极发电机相电势的特殊性使得双凸极无刷直流发电机负载工作时的换相重叠角和换相压降难以用准确表达式表示。文中研究了励磁电流、转速和负载大小对换相重叠的影响,给出各种情况下换相重叠角的对比分析,并与永磁同步无刷直流发电机的换相重叠进行了对比,从而揭示出双凸极无刷直流发电机换相重叠规律,为发电机外特性等基本特性的研究提供了依据。

Due to non-sinusoidal and unsymmetrical winding induced voltage, it is hard to give an exact expression of overlapping commutation angle and overlapping voltage in doubly salient brushless DC generator. Thus, the influences of excitation current, rotating speed and load level on commutation is first analyzed, and comparisons of overlapping commutation angles under different conditions are given. Also, the difference of overlapping commutation between doubly salient brushless DC generator and permanent magnet synchronous generator is deduced. Based on above analysis, the rule of overlapping commutation for doubly salient generator is obtained, and it provides a good guideline to the performance investigation of doubly salient generator.