Thermal Modeling of Brushless DC Motor and Brake Solenoid in Electro-Mechanical Actuators for the More Electric Aircraft Engine

This paper describes the thermal modeling of a brushless dc motor and brake solenoid for electro-mechanical actuators developed for a prototype more electric aircraft engine. Lumped-parameter thermal circuits were modeled using a commercial package for the motor. An in-house tool was used to model the transient behavior of the solenoid, which was solved using the SimPowerSystems toolbox of Simulinkreg. The models were verified with experiments using constant dc current. Temperature rise and fall look-up tables were generated from the analysis and were used for dynamic simulation of the actuator system. A dynamic electro-mechanical model of the actuator system was implemented which calculates current waveforms for given operating conditions. Dynamic coil temperatures were calculated from the current waveforms and the look-up tables. This combined method provides a useful modeling tool to simulate the thermal and electro-mechanical characteristics of the actuator.