Airflow Cooling Mechanism for High-Power-Density Surface Mounted Permanent Magnet Motor
Heating is a common problem in electric machines and cooling of small size machines is very challenging. Nowadays, the application of these machines in the actuation of weight-critical mechatronics systems is increasing. In this paper, a cooling mechanism for such electric machines with surface permanent magnet (SPM) is proposed. The mechanism is based on the fan-cooled air conditioning system except that no external impeller is needed. It has an air-inlet structure which comprise a set of six holes shrouded within a hollow cylindrical ventilation duct at the rear end of the rotor. The cooling mechanism is evaluated in a high-power-density SPM motor. The airflow rate is analyzed by developing a theoretical model using flow resistance network technique. Further verification of the airflow rate was performed with numerical computational fluid dynamics (CFD) simulation. With a discrepancy margin within 5.0%, both flow resistance network and CFD models show that the system generates a total flow rate of 118.0 L/min at maximum rated speed of the motor. Also, steady state thermal analysis of the motor using lumped parameter thermal network (LPTN) is verified in comparison with CFD simulation, which shows the cooling system maintains the motor temperature within operating range during high-speed operations.
Email Address of Submitting Authorvonflavison@gmail.com
ORCID of Submitting Authorhttps://orcid.org/0000-0002-7150-3743
Submitting Author's InstitutionYokohama National University
Submitting Author's Country