Research On The Scheme Of Speed Estimation And Parameters Idendtification Of Induction Motor

With the continuous development of power electronics, the application of AC variable speed technology becomes more and more widely. In the high performance vector control system, closed-loop speed control is an essential part. Typically, optical encoders are often used as speed sensors for the detection of speed signal. However, the introduction of speed sensor not only increases costs, but also reduces the reliability of the whole system. Whatever vector control with speed sensor or sensorless vector control, the control performance are very dependent on the motor parameters, so an accurate identification of the motor parameters will be especially important. This paper focuses on the study of speed estimation algorithms of induction motor and motor parameter identification. The speed signal is acquired by calculate the esay-to-measure quantity; Offline and online identification of motor parameters ensure the performance of vector control system.First of all, for the induction motor speed estimation, the paper introduced the model reference adaptive system (MRAS), improved MRAS method, and adaptive full-order observer speed estimation method. This paper compared estimation accuracy, steady state and transient state performance of the three methods by Matlab simulation, and select out the most stable one-adaptive full order observer method for highlighting, and applied it to the hardware system to verify its effectiveness.Secondly, for parameter identification problem, this paper presents a static motor parameters self-learning method, it's advantage lies in the fact that is not necessary to run the motor during the identification process, unlike the traditional parameter identification methods, it is suitable to many occasions which test running is not possible. In order to overcome the motor stator and rotor temperature resistance variation due to temperature changes, this paper proposes the use of adaptive full-order observer to online estimate the motor stator and rotor resistance, Matlab simulation and hardware experiments show the accuracy of the method and its feasibility.Finally, a DSP-based vector control induction motor system platform is used. The system's hardware and software processes are described in detail. The speed estimation and parameter identification techniques are used in system test platforms, accurate motor parameters are acquired and the system got good performance.