Research Of Direct Torque Controller Of Induction Machine At Electric Vehicle Based On DSP

Electric vehicle uses electricity as its energy source, so electric vehicle gives its prominent advantages to zero-let & non-pollution. Foreground of developing & researching electric vehicle is quite amplitude. The hard---core of system of electric vehicle is drive and control of motor. Direct Torque Control (DTC) of induction motor based on DSP is new technology of high performance AC--- frequency conversion--- rate of regulation.The thesis analyses drive system of induction motor at Electric automobile based on DTC. A suit of system of induction motor is designed cored around digital signal processor (DSP) combined with factual complexion of electric vehicle. The structure and performance of system is primarily discussed and analyzed. Content of research is expounded as follows:According to performance index needed by Electric vehicle, the thesis analyses drive system of Electric vehicle and advantage and disadvantage of all kinds of motor, further expounds status and development of AC--- frequency conversion--- rate of regulation. Keystone and arithmetic of DTC are analyzed by the way of space voltage vector.The thesis also introduces calculation of drive and power of induction motor. Magnetic chain and control arithmetic in different rate scope of motor is analyzed to meet characteristic of different drought of Electric vehicle. Combined with factual requirement of Electric vehicle, control of different speed gears and accelerator input are realized. Intimation system is established in the environment of MATLAB to validate these control arithmetic.The system of DTC control system is made up of circuit cored around DSP(TMS320LF2407A) and circuit cored around IPM, which realizes function of given speed gear ,given accelerator , detection and communication. The experimental system uses introduction motor as control object .Experimentation validates credibility of the system.Software of system is designed as follows: modules of initialization, gear, accelerator sampling, speed measurement communication etc are realized by programming mingled C language and assembly language. When given Gear 1, software adopts i-n magnetic chain module. When given Gear 2, software adopts u-i magnetic chain module. When given Gear full speeds, software adopts u-n magneticchain module. Control strategy of different magnetic chain module switch assures that there is biggish first-jump torque and climbing-slope for Electric vehicle when it keeps constant torque state; there is biggish speed output when it keeps constant power state. Experiments prove that the whole programme functions stably.AC--- frequency conversion--- rate of regulation of electric vehicle, combining DTC and DSP perfectly, will have enormous practical value of application.