Study on the 12-10 flux switching integrated-starter-generator for hybrid electric vehicle application

An integrated-starter-generator (ISG) system provides a cheap hybrid power strategy for hybrid electric vehicles (HEV). 12-10 flux switching integrated-starter-generator (FSISG) is one type of ISG machine, which employs the flux switching topological structure to improve the performance. In this paper, a prototype of 12-10 FSISG with the improved structure, which was employed to improve the manufacturability, was analyzed and studied. Through numerical studies, the influences of the improved structure and the characteristics of 12-10 FSISG were revealed. According to finite element analysis (FEA) results, the output voltage of FSISG can be considered as sinusoidal voltage. The results of the output torque show that the excitation current density of FSISG should be limited to less than 9 A/mm² to avoid serious magnetic saturation. Next, the experimental tests of the prototype were carried out on the testing platform. In generating mode, the experiment results indicate that FSISG can output electrical energy with high efficiency in wide speed and torque ranges. In starting mode, the maximum starting torque of the prototype is 10.5 Nm. During the starting procedure, the prototype reaches a steady state rapidly. In the variable load conditions, it shows a rapid response ability to the changes of loads. According to the experiment results in this paper, the 12-10 FSISG has shown a promising performance for HEV application in both generating mode and starting mode.