System-Level Fault Tolerance Design Process of Dual-Winding Motors for Overheat in Integrated Electric Braking System of Autonomous Vehicle

A system-level fault-tolerant design process of a dual-winding three-phase permanent magnet (PM) motor for overheat problem is introduced. Conventional dual-winding three-phase PM motors have been designed with a focus on the redundant system without considering the overheating. However, in the introduced design process, the overheating problem is considered of the motor that occurs in a faulty operation mode in an integrated electric brake (IEB) system. In the design process, the faulty operation mode is investigated in the system level. The design variables are selected as the main components of the IEB system such as the motor and pump piston. Then the selected design variables are optimized to operate without performance degradation even in the faulty operation mode. To analyze the coil temperature rise during the faulty operation mode of a dual winding motor by motor and pump piston size, a lumped-parameter thermal network with piecewise stator-housing modules (LPTN with PSMs) is utilized. In addition, to conduct the optimal design, latin hypercube sampling (LHS), kriging modeling, and a genetic algorithm (GA) are utilized. A prototype of the optimized model is manufactured and tested for verification of design results. It was confirmed that the dual-winding motor for autonomous vehicles, which is robust against overheating, even in faulty operation mode, is well designed.