An Algorithm for Effective Design and Performance Investigation of Active Cooling System for Required Temperature and Torque of PM Traction Motor

Abstract

The conventional mechanical design approach of cooling jackets serves the goal of heat dissipation to keep motor temperature below the maximum allowable limit for thermal protection. However, the desired motor performance cannot be effectively achieved by this approach since it only employs heat transfer mechanism. Therefore, a detailed algorithm is developed to provide a constructive cooling design process to achieve the desired performance of a permanent magnet (PM) traction motor. In the preprocessing stage, a two-way electromagnetic (EM) and thermal co-analysis method is developed for preinvestigation of motor temperature and torque to set the goal for the cooling requirement. In the solver, a shape and size optimization method is utilized to get the optimal cooling design for fulfilling the requirement. Further, a multiphysics finite-element analysis model is developed for structural optimization to ensure safe minimal weight of cooling design for the improvement in torque and power density. In the validation step, unlike using only computational fluid dynamics (CFD) to predict motor temperature, a two-way coupling of EM and CFD model is utilized to ensure the design goals of both torque and temperature for several operating conditions. Finally, the design optimization of a cooling jacket for an interior PM synchronous motor is conducted by implementing this algorithm.