考虑饱和及叠片涡流的凸极同步发电机空载齿谐波电势研究

凸极同步发电机空载电压波形主要取决于齿谐波电势,它叠加于由励磁磁势和气隙不均所产生的基本磁场的谐波电势上,使空载电压波形畸变率增大。本文先用有限元法求解饱和的基本磁场,再用饱和齿谐波比磁导对该磁场的调制作用算出第一类齿谐波电势。由于第一类齿谐波附加磁场割切阻尼绕组和磁极叠片引起叠片涡流和阻尼条高频电流,又会在气隙中产生第二类齿谐波磁场并在定子绕组感应出第二类齿谐波电势。本文作者在83、85和87年三次全国机电学术年会上宣读的论文主要的进展是计入了气隙圆周各点不同的饱和效应,而且首次测定和分析了磁极(A_3钢叠片)涡流对气隙磁场的阻尼作用。

Researches on the no-load tooth-ripple emf of salient-pole synchronous generators in consideration of magnetic saturation and eddy currents in the pole laminations

The no-load emf waveform mainly depends upon the tooth-ripple emf, which superimposes on other "harmonic emfs caused by the fundamental exciting field under non-uniform airgap and deteriorates the no-load emf waveform deviation ratio of salient-pole synchronous generator Firstly in this paper, the saturated fundamental field was solved out by FEM method, and then by modulating that field with the saturated tooth-ripple specific magnetic permeance, the first kind of tooth-harmonic emf was obtained. Because of the relative motion between the correlative first kind tooth-ripple auxiliary field and the rotor poles, high tooth-frequency currents will te induced in the damper windings and the pole laminations, which in turn will produce the second kind ohf tooth-ripple auxiliary field, and cause the second kind of tooth-harmonic emf appearing in the stator windings. The main contribution of this paper other than those we presented on the three national conferences qf electrical machines during 1983 to 1987 lies on. the consideration of the effects to the airgap field both from magnetic saturation and pole-lamination eddy currents.