Study Direct Torque Control Of Asynchronous Motor Based On Speed-Sensorless

The paper primary studies speed-sensorless direct torque control system of asynchronous motor in-depth therefore, and introduced a new method of switch voltage vector that don't have zero voltage vector. We built a model of direct torque control system by Matlab/Simulink, and simulation the direct torque control system by the new vector list, and find that stator flux don't aberration in lower speed by the vector list, and the system have good performance.The paper studies the advantage and disadvantage of every stator flux observer, and study two observer that have good performance. There are modified integrators and improved full order voltage-current model flux observer, and simulation the two methods in DTC system by Matlab/Simulink, and find that there are have good performance.The paper study every method achieve speed-sensorless, and compare every method's advantage, and indicate the disadvantage of every method. The paper study how to used model reference adaptive system (MRAS) and extended kalman filter (EKF) achieve speed-sensorless technology in-depth. The paper introduce a new adjustable model and status equations for take into account the advantage of direct torque control system, and introduce the expressions of MRAS and iterative arithmetic of EKF by the equations. The paper simulation the two methods in DTC system for make sure feasibility. And find some problems of the method by simulation, the paper introduced the improved methods, and simulation the improved methods in DTC system for make sure feasibility, and find that the two improved methods have good performance.In the end, the direct torque control system of asynchronous motor have designed by TMS320F2812 DSP, and achieved speed-sensorless by model reference adaptive system by assemble language, for compared, the hardware system have speed sensor.