Numerical Calculation Of Electromagnetic Fields And Temperature Fields For Salient Synchronous Motor In The Process Of Starting

The starting of salient synchronous motor is a very complex process. To describe the physical process exactly it is necessary to analyze it from the aspect of coupled fields which including electromagnetic fields and temperature fields. It is usual for motor to start frequently or start under heavy load, yet electromagnetic relation changed greatly during starting and stopping. Due to skin effect impact currents are created in starting windings, and result in heat effect which make the temperature of starting windings increase greatly in short time obviously, and lead component structure to be deformed and even make starting windings be burned out.From the aspect of practical application, this paper studies electromagnetic fields and rotor temperature rise change of salient synchronous motor in the process of starting. Firstly, 2-D electromagnetic mathematic model is built by using of electromagnetic theory and variation method during the process of starting of the salient synchronous. Dispersion format and the process of element analysis and collectivity combination equation of time-varying field are given. The solved region, boundary condition and assuming condition of salient synchronous motor are defined at the time of starting. Finite Element Method (FEM) is used to calculate the damping bars current of salient synchronous motor at different instant in the process of starting. Secondly, functional and dispersion format of 3-D transient temperature field is derived on the basis of 3-D steady temperature field. From the aspect of weak coupling of coupled fields the temperature field distribution of salient synchronous motor in the process of starting are calculated. Finally, TZ99/51-6 salient synchronous motor is taken as an example, whose 3-D transient temperature fields are calculated, and by comparing with the actual value to test the accuracy of calculation.