Study On Direct Torque Control System Of The Induction Motor Based On DSP

The DTC system has been widely used in recent years with its simple structure and static-dynamic capability since the theory of DTC was put forward in the 1980s. Based on the analysis of DTC theory and the simulation of the DTC system, the digital software design of the controlling system is realized with DSP TMS320F2812 in this thesis. And the thesis is divided into 4 parts.In the first part, the development of technology on Adjustable Speed AC Dirve is introduced. And the theory of DTC is analyzed. Besides the two classic DTC strategy, the hexagon flux track and approximate circle flux track controlling system, the thesis introduces some DTC strategies modified and some new controlling arithmetics.In the second part, with the simulation tool Matlab/Simulink, the simulation experiment on hexagon flux track controlling DTC system and approximate circle flux track controlling DTC system is realized. Especially for the latter system, the operation of the start-up, low-speed, middle and high speed, field-weakning is simulated and analyzed. And the stator start-up current limitation is simulated and the effect of changing width of hysteresis loop onto the system is also analyzed.In the third part, the DTC experiment hardware system based on DSP is constructed, which is composed with two main parts, the controlling circuit (TMS320F2812) and the inverter circuit (IGBT). Other peripheral circuits are demonstrated in detail, such as the speed detection, the voltage and current sampling, the communication interface, and so on.In the last part, with program language C, every module in the DTC system and the controlling arithmetic are constructed. At last, the simulation experiment with the induction motor module is completed based on DSP.