贯流式水轮发电机空载电压波形优化与阻尼条发热抑制

改善空载电压波形、降低阻尼条损耗发热是优化电能质量、保障发电机与电网运行稳定性的重要问题。为此,采用调节阻尼绕组节距与定子斜槽措施相结合的设计方案,对1台30MW的大型贯流式水轮发电机空载电压波形和额定负载工况的阻尼条损耗发热进行了优化设计,并利用多层运动电磁场场路耦合时步有限元模型和三维温度场有限元模型进行了分析与计算。结果表明,在合理增大阻尼绕组节距的基础上,结合斜槽措施,既能明显地优化空载电压波形,又能有效地防止阻尼条过热故障的发生。计算结果与实测数据相符合。该研究结果对提高发电机的设计水平并改善发电机与电网的运行稳定性具有参考价值。

No-load Voltage Waveform Optimization and Damper Bars Heat Reduction of Tubular Hydro-generator

Improvement of no-load voltage waveform and optimization of damper bars heat loss are important problems for designing tubular generators and ensuring operation reliability of the generators and electric network.Consequently,the no-load voltage waveforms of a 30 MW tubular hydro-generator were optimized and the damper bars heat was reduced with the design scheme by adjusting damper bar pitch and skew stator slots,and the computations were implemented and analyzed by multi-slice moving electromagnetic field-circuit coupling model of the hydro-generator and 3D temperature field finite element(FE) model of the rotor.The results show that the waveforms of the no-load voltage are improved observably and the temperature of damper bars is reduced observably when reasonably increasing damper bars pitch and skewing stator slots.The calculation results are coincident with the test data.The research is helpful for improving design standard and enhancing the operation reliability of the large hydro-generator and electric network.