The Disadvantageous Influence and Improvement Measures of Stator Slot Skewed Structures on the Damper Winding Loss and Stator Core Loss of Tubular Hydro-Generators

In this paper, a 34-MW integer slot tubular hydro- generator and an 18-MW fractional slot tubular hydro-generator were selected as examples to study the influence of the stator slot skewed structure on the damper winding loss, the stator core loss, and the no-load voltage waveform. The conclusions showed that although the stator slot skewed structure undoubtedly helped in improving the quality of the generator's no-load voltage waveform, it led to a significant increase in the eddy current loss of the damper winding and to an uneven distribution of the damper winding loss and stator core loss, which means that along the axis direction of the generator, the density of the damper winding loss and stator core loss significantly increased with the increase in the stator slot skewed degree. On this basis, the necessary measures for overcoming the above-mentioned disadvantages were discussed. Overall, the conducted research in this paper has direct and important reference values for improving the design and manufacturing levels of tubular hydro-generators, reducing their losses and heat, and optimizing their power quality.