AUTHOR : 방량, 권순오, 정재우, 홍정표, 하경호
ORGANIZATION : 대한전기학회
JOURNAL :
YEAR : 2005
VOL :
ISSUE : 하계학술대회 논문집
PAGE : 1204 ~ 1206
In this paper, an exact model of interior permanent magnet (IPM) motor is presented for analyzing of the air gap field and determining of the cogging torque, in which conformal transformation technique is used to made the motor optimization process easier.
In order to obtain an optimal IPM motor configuration for a given application, several motor parameters should be analyzed. One of the most important motor characteristics is the cogging torque. As it represents a ripple in the total motor torque, the cogging torque is parasitic, and it should be minimized during the motor design.
For all the method that can used to reduce the cogging torque, various characteristics of the motor should be fully analyzed. So, an efficient and simple analytical method is necessary for motor analysis and optimization design. Conformal mapping is a very powerful method to solve two-dimensional (2-D) magnetic fields. Using this method, the initial motor geometry is transformed into a simpler one, for which the magnetic field can be solved analytically. In this present IPM motor model, conformal mapping is presented that transform the cylindrical rotor to a square region which is help to consider of saliency effect because of IPM, and then the slotted stator surface mapped to a real axis region so that the precise slots effect on the air gap area can be exactly calculated. By considering about the effects, PM field can be precise analyzed, furthermore cogging torque and other motor characteristics can be calculated exactly.
To validate the accuracy of proposed analytical method, results are compared with the finite element method (FEM) results. Then by using the proved method, the optimization of reducing the cogging torque in the design in which various motor parameters can be varied at the same time for getting the finial IPM motor optimal configuration design.