Research Of Speed Sensor-Less Direct Torque Control System

A speed sensorless direct torque control (DTC ) system that uses TMS320LF2407A DSP as its core is designed in this paper. The method of flux observer and speed estimation is researched.Integral method based on u-i model and flux state observer are researched by MATLAB simulation, the result shows that flux state observer can overcome the disadvantage of integral method. Based on this flux state observer, direct speed calculation and adaptive speed estimation are verified by simulation.Finally, the control circuits are designed based on TMS320LF2407A. Integral method, flux state observer and adaptive speed estimation have been implemented in 1.1kW induction motor by assembly language. The result proves that flux state observer can overcome the effect of stator resistor and improve the performance of machine at low speed; adaptive speed estimation can convergence to real value fast and accurately.