Torque Estimation Of Asynchronous Motor

As an important component of transmission system,the three-phase asynchronous motors are widely used in industry, agriculture, national defense and so on. However, the existing torque sensor was expensive, and the structure was complex,. And the installation and maintenance of them are difficult. All of those reasons limit their applications in the real-time measurement on electric transmission systems. Therefore, torque is estimated indirectly by detecting voltage, current and rotate speed signal in this paper. The main contents have following aspects.The modeling method of dynamic model and static-state model of asynchronous motor as well as the coordinate transformation are summarized in this paper. The influence on rotate speeds and torque due to varying parameters are discussed. And simulations on asynchronous motor are carried out based on the Simulink platform.In view of the instability of PSO identification result, the Multi-PSO-Weighted method is proposed in this paper, which enhanced the stability of PSO identification results. The method is used in the parameters identification of dynamic model as well as static-state model and the simulation results indicate that the method is feasible. And then, the torque is estimated respectively. As different properties are reflected by the dynamic model and static-state model, one multi-model weighted fusion method which is used to estimate the torque is proposed in this paper. Simulations on the asynchronous motor are carried out based on the Simulink platform. indicate that the method is feasible.Experiments on an actual asynchronous motor are performed which include the non-load experiments, blocking experiments as well as the rotate speeds modulation experiments. The influence on the motor parameters due to the temperature is analyzed. The experiment results demonstrate that the method is practicality.Finally, the paper is summarized, and the questions as well as the direction which need deep research are concluded.