Research Of Characteristics And Optimal Design Of Interior Permanent Magnet Synchronous Motor

Iterior permanent magnet synchronous motor (IPMSM) adopts permanentmagnet excitation method and has simple strcture because of it cancelled thebrush and slip ring device.Thus it has a higher energy density compared withother types of motor with the same capacity, therefore it is widely applied in avariety of occasions in recent years. In this paper, two aspects of the motor willbe illustrated, the first one is electromagnetic field and the second one is thethermal field with the characters of380V,11kW.1. In terms of electromagnetic field, firstly the two dimensionalelectromagnetic finite element model of the protype was established by usingthe Ansoft software, and got the magnetic field distribution,flux dendity ofair-gap and torque-angle characteristic curves of the motor in magnetostaticmodule, and the electrical angle of maximum torque was obtained.2. Corresponding relation between the stator three phase current and the directand quadrature axis inductance was deduced, based on which the paper got thechanging rules of d and q axis inductance with different armature current incertain cases. All of these are prepared for system with changing parameters.3. In the transient magnetic field, the dynamic performance was obtained firstly, including the rated power factor, efficiency and torque ripple, etc. Thenby using analytical method, cogging torque under different approximate numberof mathematical expression and the corresponding amplitudes was calculatedand comparing with the finite element results. At the same time throughparametric analysis it is concluded that the cogging torque, along with thechange of some important parameters in preparation for the optimization design.4. Taguchi method was used to analyze the motor, high efficiency and smalltorque ripple coefficient as the goal, through the optimization of the stator slotwidth, permanent magnet length width and thickness of magnetic separation ofmagnetic bridge, etc. At last an optimized design scheme was obtained, and thecorrectness and feasibility of the scheme was verified through the finite elementsimulation.5. ANSYS APDL command flow way was used to set up the thermal fieldanalysis of two-dimensional finite element model. Then based on the basictheory of heat conduction in the motor internal model to solve the motor parts ofheat transfer coefficient of correlation, and in a thermal steady state andtransient heat field simulation analysis. In the thermal steady state field, no-loadand rated load status was analysed to got the temperature and heat fluxdistribution. Rated in the thermal transient, the result of steady state field was asthe initial value, the analyzed the distribution of temperature and heat flow in thelater10minutes and compared with standard values of B.