Research Of Direct Torque Control In Electrical-Magnet Synchronous Motor

In this dissertation, the direct torque control ( DTC ) system for sensor-less electrical-magnet synchronous motor is studied profoundly. Based on the research of limitation of classical direct torque control (DTC) system, the stator flux observer has been designed, and sensor-less synchronous motor system of direct torque control has been introduced by high performance digital signal processor (DSP), which enhanced the performance of the system.Based on the classical DTC inherent limitation, the SVM and DTC are combined to reduce the torque fluctuation, by sending more voltage vectors to approach actual vector. Based on the investigation of the influence of different vector to the torque variation, the switching table is improved and optimized, and take a flux and torque two-level switching table. Simulation and experimental results show that the torque of motor can be improved largely without degrading dynamic performance of system, and the torque ripple is weakened greatly.In the end, the electrical-magnet synchronous motor system of direct torque control has been designed by TMS320VC33 DSP, and the real-time controller software is written by C mixed with Assemble language, the research of digital realization and the software design is carried out. Many high performances have been attained.