汽轮发电机不同负荷时电磁场的分析与计算

Analysis and calculation of electromagnetic field of turbo-genertors on different loads

准确计算电机电磁场的分布可以为进一步确定电机参数、性能曲线、温升等奠定基础,因此电机电磁场的分析和计算是电机设计和制造的主要工具之一。基于此,建立了大型汽轮发电机电磁场的数学模型。考虑到定、转子齿槽的影响、气隙磁场的扭斜等因素,分析了电机整个圆周上的磁场分布。采用有限元数值方法计算了电机空载、额定负载以及任意负荷时的电磁场分布,分析过程中考虑了导磁材料的非线性。采用电磁场的计算结果确定了电机定子铁心的损耗,并将其应用于定子温度场的计算,计算结果与发电机运行时的实测值相比较,误差满足工程需要,证明提出的模型和方法是正确的。

It is a basis of defining electrical machines parameters, performance, temperature rise and so on to calculate its electromagnetic field accurately. Thus, the paper presents mathematical model about electromagnetic field of turbo - generators in which the whole circle of generators is calculated considering influence of teeth and slots, skew of gap magnetic field etc. The finite- element method （FEM） is used to calculate electromagnetic field when generators operate on no- load, rated load and other loads in which the nonlinear of magnetic conductor is considered. The iron loss of stator is determined by magnetic field and is applied on calculation of the temperature field of generator. The proposed method is validated to be correct by comparing calculation and measurement values.