Design of a permanent magnet motor with wide temperature range

Abstract

We present the design of a permanent magnet synchronous motor (PMSM) for wide temperature range applications. The designed motor will operate within a temperature range of −60 °C up to 300 °C, have an output power of 12 kW at 12 krpm rotating speed, and maintain an efficiency greater than 90%. The design calls for good performance over a speed range of 8 krpm to 16 krpm. The stator material in the current design is Hiperco50 and the permanent magnet (PM) material is Samarium Cobalt (SmCo). Special wire insulation is applied to the stator windings. Previously, magneto motive force (MMF) was simply calculated by multiplying the total magnetic field intensity of the air gap by the length of the air gap. This method is not accurate if the designed air gap is large, such as in a PMSM design. In this paper, we have analyzed the mathematical model of the air gap and describe the MMF by an expression in terms of a logarithm function. We have analyzed the effects of temperature variations on the residual flux density, copper loss, core loss, and windage loss, etc.