Study of induction motor direct torque control for speed sensorless

For the disadvantage of the induction motor direct torque control system´s performance when it runs in a low velocity, the full order flux observer is used to achieve the stator flux observation, On the basis of the closed-loop flux observer, the speed adaptive observer is constructed based on MRAS. The new method of pole placement is Proposed to achieve the configuration of the flux full order observer gain matrix parameters. Simulation results show that In the case of the motor parameters, not only the robustness of the observed flux is improved, but also the convergence speed and velocity to estimate accuracy is improved.