基于开放绕组的新型无刷谐波励磁同步发电机

A New Type of Harmonic-Current-Excited Brushless Synchronous Machine with Open Windings

在开放式绕组发电机中,三相定子电流可以包含完全相同的谐波电流成分,例如3次谐波电流。本文据此提出了一种新型的无刷谐波励磁同步发电机结构。与已有利用转子磁场所包含的3次谐波磁场的励磁技术不同,该原理利用定子开放绕组中的3次谐波电流成分或高频单相电流成分或直流成分所产生的定子脉振磁场在转子谐波绕组中产生感应电动势,经整流后为转子励磁绕组提供励磁电流,从而在不采用独立励磁机的前提下实现无刷化的电励磁同步发电机。本文对该谐波励磁原理进行了理论分析及电磁场有限元计算验证,并在此基础上进行了样机实验验证,证明了该原理的可行性。该谐波励磁原理的意义在于,提供了一种无刷励磁的同步发电机方案,以期减少高性能发电机对日益昂贵的稀土永磁材料的依赖与消耗。

In an open-winding machine, the three-phase stator currents can be controlled to contain the same harmonic current components like the third harmonics. This paper introduces a new harmonic current excitation principle in synchronous machines based on open winding controls. Unlike existing harmonic excitation technologies which utilizing the third harmonic components of rotor magnetic fields, this brushless harmonic excitation principle is realized by injecting the third harmonic current component or high frequency single-phase current component or DC component into the three phase stator open windings, to generate a time pulsating magnetic field which can induce back-EMFs in the specially designed rotor harmonic coils. Through rectification, the induced back-EMFs are used to supply DC current to the rotor excitation winding. To verify the above principle, magnetic field calculations and prototyping tests were carried on. The significance of this harmonic excitation principle is to provide a new brushless machine option to reduce the consumption of increasingly expensive rare earth permanent magnetic material by machines in some applications.