交流励磁电机系统的谐波分析

Harmonic analysis in AC excited generator systems

交流励磁电机和交交变频器是交流励磁电机系统中最主要的两个谐波源。交流励磁电机的参数计算采用多回路分析方法，计及空间气隙谐波磁动势和定、转子齿槽效应；交交变频器采用面向线路的模型，并加入两管换流模式和正、负组换流模式。仿真结果与实验进行了对比，并在此基础上，详细讨论了：１）交交变频器两管切换、正负组切换对系统谐波的影响；六脉波与十二脉波变频器的谐波比较；２）交流励磁电机的空间气隙谐波磁势，定、转子的齿槽和定、转子短距系数对系统谐波的影响。归纳了交流励磁电机系统中谐波的抑制措施。

AC excited generator (ACEG) and cycloconverter are principal harmonic sources in ACEG systems. Using multi loop analysis method, spacial gap harmonic magnetmotive force (MMF) and slot effects of the stator and rotor of ACEG are calculated. Circuit oriented model of cycloconverter is developed by adding tube changing mode and group changing mode. The simulating results agree well with experimental results. Based on these, the paper discusses systematically: 1) effects caused by cycloconverter's tube changing and group changing; harmonic comparison between 6 pulse and 12 pulse cycloconverter; 2) effects of spacial gap harmonic MMF, tooth slot of the stator and rotor and short span coefficient of ACEG. At the end of this paper, harmonic restraining measures of ACEG system are presented.