Thermal analysis and control development of interior PM traction machines

The paper presents thermal analysis and control development for interior permanent magnet (IPM) traction machine. Losses of the IPM traction machine are discussed and derived using measurement and finite element analysis. The loss components are then employed for steady-state and transient thermal analysis. Assuming rotor temperature obtained from transient thermal simulation over driving cycles, dq-axis current reference LUTs employing on the traction machine drive system are determined. It is shown that when steady state rotor temperature is higher than the average driving cycle temperature, maximum difference in electromagnetic torque is less than 5.5% over the torque-speed envelope.