Study Of Speed Sensorless Field Oriented Control System Based On DSP

The rotor field oriented control has brought essential advances in AC variable speed drive system. Speed sensorless induction motor drive promotes the simplicity and robustness further, so the sensorless field-oriented control (FOC) technology is one major direction of motion control. In the technology the key problem is how to estimate the speed and the flux of the rotor. Based on the former researches, the speed estimation and rotor flux observation methods are studied using the theory of Model Reference Adaptive System (MRAS).In this paper the tendency of motion control is introduced first. Next the basic field-oriented control principle and coordinate transformations are presented. The mathematic models in the different reference frame are also proposed. Then the paper discusses the implementation of a new kind of rotor flux and speed observer based on a model reference adaptive system, and a speed sensorless field-oriented control system using PI controller for induction motor is presented. By the referenced model and the adjusted model are established, the output error of that two models is close to zero through the adaptive institution adjusts parameters of the adjusted model. And ensure the system also has better performance, if there is existing interference or the dynamic change is taking place in the system. Besides the model of the control system is established, also the simulation results show the MRAS-based field oriented control system is accurate and effective.Experiment is based on the DSP (TMS320F240) design system for digitalmotor control. Software programs carry out algorithm to estimate the rotor speed and fluxes, and space vector pulse width modulation algorithm. The satisfied experimental results prove that the speed sensorless drive system based on which has good static and dynamic performance.