Study On Speed Sensorless Direct Torque Control System Based On DSP

Direct Torque Control (DTC) technology is a high-performance adjustable speed method with fast torque response. In this thesis, a speed sensorless DTC system is studied, which based on DSP of TI inc.-TMS320F240 .Fundamental principle and implementation method of DTC are introduced in detail in this paper. In DTC system, the concept of space vector is introduced to analyze and control the AC motor, the electromagnetic torque and flux are caculated and controlled in the stator reference frame, and the optimal PWM gating signas are generated to control the inverter according to the output of the Bang-Bang regulator.In this paper ,the DTC system is designed based on DSP.A speed estimation method is derived detailedly and the sensorless speed close-loop control is conducted.In this system,there are some problems,such as flux drift and torque ripple.To resolve these problem,a modified flux caculation method and some measures such as speed LPF,torque slide filtering are adopted.The system performance is enhanced by these mersures.The system control software is designed in assemble language based on the hardware fundament with using TMS320F240 as core and a speed sensorless DTC algorithm is realised. The experimental results indicate that the design of this system is successful. The system has stable performance with fast response, so to some extent it is a practical useful system...