Research Of Induction Motor Direct Torque Control System

Direct Torque Control technique referred to as DTC,it is Following the vector control technology,developed another new, high dynamic performance frequency control technology. the control structure issimple, easy to implement all-digital features. But its torque ripple is large, the starting current is too large,such as inadequate hindered its development and application.. In this paper, for the induction motor directtorque control system performance expand theoretical and experimental studies, the main contents are asfollows:(1) describes the basic structure of induction motor direct torque control and the basic principles of thesystem, starting from the mathematical model of induction motor stators coordinate system, flux observer andspace voltage vector, study investigated the direct torque control system performance.(2) for the problems of direct torque control at low speeds, the system uses two PI controller to adjust thecorresponding flux with torque respectively, in order to obtain accurate flux with torque compensation spacebaseline reference voltage vector. For controlling the inverter switching state SVPWM control strategy isadopted in order to improve low-speed performance. Experimental results show that the proposed schemewould not only greatly reduce the torque ripple, and easy to implement.(3) to obtain more detailed plan in full argument on the basis of motor control chip TMS320LF2808asthe control core experimental operation, in order to design the control system. Including the main circuit, apower circuit, a signal acquisition circuit and other hardware. DSP system software through the integrateddevelopment environment CCS, to complete the work..Finally, the paper summarizes the work done, and anoutlook on future research priorities.