浅析MW级双馈风力发电机轴承电压成因

Brief Analysis on Bearing Voltage Cause of MW Grade Doubly-Fed Wind Power Generator

轴承电压是指在轴承的径向间隙中出现的电容耦合电压,对于普通电机来说轴承电压最初是由定子绕组的平均电位与接地的定子铁心之间的交流电压引起的,当电机以正弦电压供电时,实际上轴承电压是等于零的,而对于MW级双馈异步风力发电机来说,却有很大不同,不但成因与上述存在差异,而且其幅值大小及破坏力较上述亦高。同时侧重分析了MW级双馈异步风力发电机在正常运行时轴承电压的成因,指出了其与普通变频电机在此方面的区别。并在理论上提出了相应的解决方案,同时进行了实践验证。

The bearing vohage refers to the capacitance coupling voltage appeared in ra- dial clearance of bearing. For a common generator, bearing voltage is originally caused by aver- age potential of stator windings and ac voltage of the earthed stator core. When the generator is supplied with sinusoidal voltage, the bearing voltage is equal to zero in fact. But MW grade doubly-fed asynchronous wind power generator is quite different from it. Not only the causes have differences from the above, but also the amplitude and breakdown force are higher than the above. This paper focuses on analyzing the bearing voltage cause of MW grade doubly-fed asyn- chronous wind power generator at normal operation, points out its difference from that of com- mon variable-frequency generator, and puts forward the corresponding solutions in theory. At the same time,, practical verification was carried out on the generator.