Inoue, M., Takamatsu, H., Ogami, M., Ninomiya, K. et al., "New-Structure Motor for Full Hybrid Electric Vehicle," SAE Technical Paper 2016-01-1225, 2016, doi:10.4271/2016-01-1225.
The traction and power generation motors of hybrid electric vehicles need to provide greater output densities. This can be achieved by increasing output and reducing the physical size and weight of the motors. However, there are limits on how much a motor’s output can be increased while simultaneously shrinking the motor’s size, as it is conventionally structured. To address this issue, the authors developed a stator with a new structure to increase motor output and reduce motor size. By simultaneously optimizing magnetic circuit design, they increased maximum torque by 2.6% and maximum output by 8.9% and reduced volume by 23% and weight by 23% compared to motors of conventional structure, all while maintaining the same level of efficiency. The result was top-of-class output and compactness.