Fundamental Research on Axial-Axial-Flux Compound-Structure Permanet-Magnet Synchronous Machine

　　Fundamental Research on Axial-Axial-Flux Compound-Structure Permanet-Magnet Synchronous Machine
　　With the development of hybrid electric vehicles (HEVs), hybrid system is becoming the researching focus gradually. The power train system in HEV is basically divided into three types: serial, parallel and serial-parallel combined type. The serial-parallel combined hybrid system integrates the functions of the series and parallel system and has its unique advantage. The axial-axial flux compound-structure permanent-magnet synchronous machine is the key part of a novel serial-parallel neodymium magnets combined hybrid system. For the environment protection and energy conservation, it is meaningful to research the axial-axial flux compound-structure permanent-magnet synchronous machine system.Firstly, as the axial-axial flux compound-structure permanent-magnet synchronous machine being a new type of disk machine, its air-gap magnetic field distributes in three-dimension. So its simulation model is more time consuming and has higher requirement for hardware than the two-dimensional model. So the three-dimensional simulation model is researched to save computing time and hardware resource.The axial-axial flux compound-structure permanent-magnet synchronous machine is integrated by stator machine and double rotor machine.
　　The coupling between the two machines is analyzed, and the choice principle of the common rotor core is found. The pole-matching problem is researched, http://www.chinamagnets.biz and it is concluded that the two machines had better to have the same pole numbers to reduce the volume and coupling between the two machines. The static magnetic field is researched also.The paper deduces the basic electromagnetic relationship of permanent-magnet synchronous disk machine, and compares it with that of ordinary column machine. The factors that influence the power per unit volume, power per unit mass and the efficiency are investigated. According to the contrast between the compound machine and a one-stator one-rotor disk machine, the predominance of the axial-axial flux compound-structure permanent-magnet synchronous machine is obvious.Lastly, pole-arc ratio, skewed magnet and ladder-magnet are researched to improve the torque characteristic. And the effect of pole-arc ratio and skewed magnet is satisfying. So the two methods are matched and optimized again, and the optimum scheme is obtained.