Abstract
We have developed novel mathematical models of d-axis and q-axis magnetic fluxes ϕd and ϕq for permanent magnet synchronous motors (PMSMs). The models can be used to approximate magnetic characteristics using simple fractional equations with id and iq as variables. They include eight constants, and some of them represent the degree of magnetic saturation and cross-coupling. However, the magnetic characteristics are varied with the temperature rise in PMSMs, which are dependent on the load torque and motor speed. In this paper, the characteristics of the eight constants that vary with the motor temperature and the residual flux density Br are shown. Further, we propose to extend the mathematical models by considering the temperature and Br variation.
