This report investigates the design of traction motors for electric vehicles to reduce the amplitude of the current produced during a three-phase short circuit of the machine. The report focuses on surface-mounted permanent magnet machines with concentrated windings. The changes in the three-phase short circuit are compared to other performance benchmarks such as peak torque, peak power, torque density and power density.

This project found that, for a given set of boundary conditions, the performance of the motor will be reduced at the cost of lower three-phase short circuit currents. As the motor design is modified to reduce the short circuit current, the machine becomes limited by temperature and DC supply voltage. These findings achieve the goal of this project which is to quantify the compromise between low three-phase short-circuit current and performance.