巨型水轮发电机励磁电流及影响因素

Excitation current of large hydro-generator and its influence factors

为了准确地获得空载和额定负载时的励磁电流,在充分考虑直交轴磁场饱和效应的基础上,利用时变电磁场有限元法计算1000MW水轮发电机在空载和额定负载时的励磁电流.分析了励磁绕组尺寸、阻尼条节距比以及磁性槽楔等相关因素对励磁电流的影响,在获得空载和额定负载励磁电流的基础上,提出了励磁绕组尺寸、阻尼条节距比的设计准则,并从电磁设计的角度论证了磁性槽楔应用于1000MW水轮发电机上的可行性.实验结果表明,有限元法可以用于1000MW水轮发电机的励磁电流计算,为工程设计提供了理论依据.

In order to accurately obtain the excitation current under no-load and rated load,the excitation current of the 1 000 MW hydro-generator under no-load and rated load was calculated using the time-varying electromagnetic field FEM and through fully considering the saturation effect of d-q axis magnetic field. The influence of such related factors as the size of excitation winding,pitch ratio of damping bar and application of magnetic wedge on the excitation current was analyzed. With obtaining the no-load and rated load excitation current,the design criterion for the size of excitation winding and pitch ratio of damping winding was proposed,and the feasibility to apply the magnetic wedge for the 1 000 MW hydro-generator was discussed from the view of electromagnetic design. The experimental results show that the excitation current can be calculated for the 1 000 MW hydro-generator by FEM,which can provide the theoretical basis for the project design.