tailieunhanh - Analytical Method of Torque Calculation for Interior Permanent Magnet Synchronous Machines

This paper introduces a new analytical method for performing the output torque calculations of an interior permanent magnet synchronous motor (IPMSM) including both permanent magnet and reluctance torque components. | Analytical Method of Torque Calculation for Interior Permanent Magnet Synchronous Machines Seong Taek Lee 1 Student Member IEEE University of Tennessee 414 Ferris Hall Knoxville TN 37996 USA slee10@ Abstract -- This paper introduces a new analytical method for performing the output torque calculations of an interior permanent magnet synchronous motor IPMSM including both permanent magnet and reluctance torque components. This method works well when using a 2-dimensional magnetic equivalent circuit of a machine by omitting the step of calculating the inductance values which are required for the calculation of the reluctance torque. The analysis results show that this method is very useful in the first design step before simulating a model using finite elements analysis FEA . Also this method can be applied to any type of synchronous machine. Index Terms equivalent circuit inductance permanent magnet machine synchronous motors torque. I. Nomenclature BFE brushless field excitation IPMSM interior permanent magnet synchronous motor FEA finite element analysis mmf magnetomotive force PM permanent magnet II. Introduction The interior permanent magnet synchronous motor IPMSM is currently used in many industrial areas due to its advantages of high power density and efficiency. In the first step of designing a new IPMSM the magnetic equivalent circuit is widely used by many machine designers to determine the characteristic of the machine 1 - 7 . Since the output torque of an IPMSM contains the reluctance torque that is caused by the difference of the two-axes d- and q-axis inductances Ld and Lq these inductance values should be calculated from the analysis of its equivalent circuit. In other words to obtain the output torque of a newly designed machine the exact inductance values Ld and Lq are necessary 1 3 - 5 and 7 - 9 . There are many analytical methods to calculate the Ld and Lq of synchronous motors including IPMSM 1 3 4 and 10 - 11 . However it is not easy to .