Thermal characteristics study of a water-cooled permanent magnet linear motor

For permanent magnet linear motors (PMLMs), large temperature rise can damage their performance and limit their output. Water-cooling system can be designed to reduce temperature rise and to improve thrust density. In order to study the thermal performance of a water-cooled, 14-pole, 12-slot PMLM, the finite element model and the thermal network model are erected. For water-cooled type PMLM, the modeling difficulties are solved. Under continuous duty, the temperature distribution of this PMLM is investigated based on the two models, which is validated by experimental results. The effect of water-cooling system and the impact of its parameters on temperature rise are investigated. And, the influence of temperature rise on motor thrust force, and efficiency is studied. Finally, based on the finite element model, thermal characteristics of this PMLM under short-time duty and intermittent duty are studied, which find the relationship of running time and the maximum allowed short-time current, and the impact of load sustained rate.