Energy efficiency comparison of SR and IPM generators for hybrid electric vehicle

The SR generator has been designed with competitive outer dimensions, weight, maximum power and efficiency by the authors. However, efficiency maps of the SR and IPM generators are different. Thus, direct comparison has been difficult. In this paper, a comparison of energy efficiency among two designed SR generators and an IPM generator is carried out for the application for hybrid electric vehicles. It is found that energy efficiency of the SR generator is competitive or better than that of the IPM generator because the SR generator has no iron loss during idling although iron loss exists in IPM generators caused by permanent magnets.