The Optimization Design Of A Radial-radial Flux Compound Structure Permanent-magnet Synchronous Machine Used For Hybrid Electric Vehicles

Among hybrid system, the radial-radial flux composite-structure permanent-magnet synchronous motor (CS-PMSM) has the same function with the system composed of the plenetary gear and two electric machines, so it can realize the function of electronic continuously variable transmission. This thesis makes a study of a 50kW/30kW radial-radial flux CS-PMSM.Firstly the power rating of the radial-radial flux CS-PMSM is selected, so is its number of poles and its slot/pole number combinations. On this basis, the two motors which constitute the radial-radial flux CS-PMSM are redesigned. And then their two-dimensional finite element simulation models are established separately, so the simulation results of their performance can show the rationality of the design.Then the cogging torque of the radial-radial flux CS-PMSM is optimized. After the choice of slot width and pole arc coefficient as optimization parameters, firstly the two motors are optimized separately, and then the changes of their respective cogging torque are analyzed while the two motors turns in the same direction and reverse. The cogging torque and load torque fluctuations of the radial-radial flux CS-PMSM before and after optimized are compared and analyzed.As the two motors of the radial-radial flux CS-PMSM have common external rotor, not only check each other in structure, but also bring the matter of magnetic coupling. The magnetic decoupling is achieved by the design of two motors. And the thickness of the outer rotor core is reduced at full steam while ensuring the outer rotor core is not saturated, so it can increase the power density of the radial-radial flux CS-PMSM. Finally the extent of the magnetic field interference is assessed by finite element method, and the load torque of the two motors is compared when they run at different load conditions. Finally approves that the two motors of the radial-radial flux CS-PMSM can run independently without interference.Last the two-dimensional finite element thermal model of the radial-radial flux CS-PMSM is established, and simulate the temperature distribution of the radial-radial flux CS-PMSM using water-cooled and air-cooled, and the simulation results show that it can run at rated condition stably.