Study On The System Of Direct Torque Control Based On DSP

It is always used for speed control by direct current motor, because the direct current motor may realizes the stepless speed regulation by changing armature voltage as well as adjusting the exciting current.But the direct current motor is sure of a lot of problems such as that the structure is complicated, it is very expensive,at times it has commutator spark consist in mechanical commutator and electronics brush, and most of important is very difficult to repair direct current motor. Along with the production technology's development, the time is coming that the exchange velocity modulation technology substitutes for the direct-current velocity modulation technology gradually.Asynchronous motor is multivariable,close coupling and non-linear system that is variational with the time going.The theory of direct torque control is soluting the problem very well.The flux and torque of stator of AC induction electromotor are calculated and controlled in the stator-oriented coordinates, are adopted stator magnetic field orientation, are directly tracked.The signal of PWM is builtby dint of the discrete adjustment in order to control optimally the state of the switches ofinverter and get the high dynamic performance torque response.In the environment of Matlab/Simulink, the paper uses the power system block to build a mathematic mode based on the principle of DTC system and has done some simulation. The result of the simulation proves that the trajectory of the magnetic link is almost circular, the rotor speed follows the given speed.The hardware circuit of the system adopts the AC-DC-AC topological structure. The system uses TMS320LF2407A DSP chip which is specialized in motor control system by Texan instrument company.The chip contains many special modules for motor control and decreases many peripheral instruments. The newest Intelligent Power Module is used for power instrument core, it is correspond to DSP by electric coupling electric circuit. I give the whole software design.Finally, this paper completes the simulation debugging of the open loop start and the closed loop motion,we have analyzed the experimental result, summarized design success and the insufficiency in this system and at last forecast the direct torque control present's development.