Simulation Research On Compound-Structure Permanent-Magnet Synchronous Machine System Used In Hybrid Electric Vehicles

The compound-structure permanent-magnet synchronous machine (CS-PMSM) system is a novel drive system used for hybrid electric vehicles (HEVs), and it becomes one of the most competitive and ideal drive systems due to its compact structure and advantages of series-parallel hybrid. In this thesis some research has been carried out on the CS-PMSM system, which is the key part in the hybrid drivetrain.Firstly, in order to analyze and better control the CS-PMSM, the mathematical models without and with considering the cross-magnetization effect are set up respectively and compared, and then the control block diagram of the CS-PMSM is configured in the MATLAB/SIMULINK based on the established mathematical model.Next, the control strategy of the CS-PMSM is investigated and established according to its special structure and application. Different control strategies are applied for the two machines: the DRM performs the torque control, and the SM carries out the speed control. Aiming at different control strategy for each machine, the concrete control methods are further investigated. Firstly, different vector control methods are employed for both machines according to their characteristics and output- performance demands: the DRM implements the id=0 control, while the SM carries out the maximum torque per ampere control during the constant torque region, and flux weakening control during the constant power region. Secondly, the direct torque control method is investigated and applied for both machines. The feasibilities of the vector control and direct torque control methods are both validated by the simulation results in the MATLAB/SIMULINK, and these two methods are further compared. The optimum control methods are finally established for the DRM and SM, i.e., the DRM employs the direct torque control method and the SM applies the vector control method.Lastly, by replacing the generator, motor, and planetary gear in the Toyata Hybrid System (THS) with the CS-PMSM, the CS-PMSM system and THS are compared and the integrative evaluation of the CS-PMSM system used in HEVs is presented.