Coupling Calculation Of Electromagnetic Field And Temperature Field And Cooling System Design For PM Servo Motor

This paper makes a systematic in-depth research for permanent magnet motor core loss, permanent magnet eddy loss and electromagnetic field and temperature field coupling calculation, main research work has the following several parts:Firstly, core loss separation calculation model combined with two-dimensional time step finite element method is used to analyse permanent magnet servo motor; core loss coefficients are obtained according to loss curve of different frequencies; permanent magnet eddy loss mathematical model of servo motor is given; considering that subdivision influence on calculation result, the appropriate subdivision accuracy is selected to calculate the stator core loss and permanent magnet eddy current loss, and the influence is researched on harmonic loss of the load current.Secondly, considering the influence of different structural parameters on two kinds of loss, it is separately analysed from extremely groove cooperates, air gap length and slot open. It is summarized the influence to losses with structural parameters change, and some methods are researched to reduce losses.Then, on the basic of loss calculation, the coupling field calculation method is researched and the coupling field calculation flow chart is given. Comparing experimental results and calculation results, the appropriate conductivity coefficients are designated by multiple corrections. By calculating the coupling field of permanent magnet servo motor, temperature rise of all parts of motor including the highest and lowest temperature rise is obtained. It is discussed the influence of temperature rise on motor stator core loss and permanent magnet eddy current loss, and the calculated results are compared with the experimental data. By error analysis, it is pointed out the causes of errors.Finally, the cooling system of disc permanent magnet motor is designed and the ultimate program is determined. The appropriate conductivity coefficients of thermal conductive materials are designated by multiple corrections. According to the flow chart of the coupling field calculation, temperature distribution of the motor is obtained. It is analysed the error of coupling field calculation results, the temperature field calculation result and the experiment value,and it is explained that the coupling field calculation is more accurate.