Direct Torque Control Of Permanent Magnet Synchronous Motor For Hybird Electric Vehicles

The dissertation is presented to the study on permanent magnet synchronous motor (PMSM) drive system for the tandem hybrid electric vehicles (HEV) application. Direct Torque Control (DTC) method is quoted from drive characteristic on electric motor control witch through theoretical analysis, computer simulation or experimental validation. The Maximum Torque Per Ampere (MTPA) control has be introduced for optimizing the traditional DTC method which could ameliorate the control performance. For more speed governing scope, field-weakening control has been carried out above the basic speed. Enhancing the field-weakening capability could upgrade high speed performance for HEV running. The main contributions of dissertation as follows:Firstly, the MTPA control strategy in constant torque area strategy in constant power area is analyzed through structuring the PMSM mathematical mould, which the DTC method on PMSM has been studied further deeply. The influence of different parameters on the PMSM output power, torque and extend speed capacity witch has be analyzed. The field weakening control strategy in constant power area is analyzed through structuring the PMSM mathematical mould. The modified parameters switching method has be applied in the constant torque area and the constant power for simulation. The more effective DTC method witch combines MTPA has be compared with traditional DTC could reduce more ripples of the DTC in the low speed region. The simulation analysis could pave for the further experiment research with foundation.Secondly, the PMSM DTC control system test-bed has be build including both the software and hardware of the Based on TI company DSP designed for motor control on TMS320f2812 micro-chip for a full-digital PMSM control system. The hardware drive design for DSP interface circuit and the power control circuit combine with C computer language program for DTC been studied further deeply in DSP.Finally, the experiment has been done for the research. Results of the experiment and simulation indicate validity of the reducing speed and torque ripples from traditional DTC in low frequency running and the field-weakening method for HEV which introduced in the paper.