Thermal Quantitative Analysis and Design Method of Bistable Permanent Magnet Actuators Based on Multiphysics Methodology

A thermal model of bistable permanent magnet actuator (BPMA) was established and verified using multiphysics methodology. By treating the nonsimplified energy consumption distribution as the heat source for temperature field calculation, the established thermal model adjusts the material properties by temperature and considers the interaction between motion and loss. The distribution and change of loss and temperature rising were quantitatively analyzed. Moreover, a design method for an electrical parameter was proposed under thermal constraints based on quantitative analysis. The results showed that armature iron loss and coil copper loss accounted for 24.7% and 42.8% of the total loss, respectively, which could be regarded as the main components of heat source. The balance temperature of armature was the highest, followed by that of coil, cover, sleeve, and PMs. The limiting temperature of the actuator was equal to PM's limiting temperature. Through electrical parameters optimization design, the prototype met the requirement of continuous working time under limiting temperature, with the response time decreased by 6.9%. In addition to being applied to BPMA, the proposed method can be used for analysis and design of a wide range of electromagnetic actuators.