The Research And Design Of Servo Driver Based On DTC

With the development of power electronics technology, modern control theory anddigital signal processor, Servo System has been widely used in industrial production. As weknow, the core of the servo system is servo motor and servo drivers. Some big companieshave had relatively servo products. But in our country, for high performance servo products,we still depend on imports. In this situation, this thesis gave the research and design on theservo drivers based on the PMSM.The structure of this thesis was divided into two parts, theory research and constructionof experimental platform. Specific content is as following.First of all, through the study of PMSM mathematical model, I have made the researchon both the traditional DTC that was based on switching table and the SVM-DTC that wasbased on the SVPWM. According to decrease the flux and torque ripple, using space voltagevector to replace the switching table to improve system’s dynamic, static performance. Thesimulation result also showed that the strategy based on SVM-DTC could apparentlydecrease the flux and torque ripple, what’s more the waveform of stator current was smooth.Then, I’ve made an analysis on the scheme of sensorless speed control. Based on theadvantage and disadvantage between kinds of arithmetic, I accomplished sliding modelobserver in SVM-DTC. In order to solve the speed’s ripple and position error, I addedextension kalman filter instead of common filter in the model. The simulation showed thatadding EKF could decrease the speed’s ripple and improve the accuracy of rotor’s position.At last, I accomplished to construct the platform of servo drivers, including hardwareand software. The main work in the hardware was to design and accomplish two modules.One module is about core control based on DSP, the other is about power driving based onIPM. The control module was mainly about the minimum system of DSP. The power drivemodule was mainly about IPM’s surrounding circuit, current and voltage collecting circuit,optically coupled isolation circuit, protect circuit and so on. The software was designed inmodules, which including main program and interrupt subprogram. The whole software hasbeen done in CCS2.0. Through compiling and building, I have finished motor start, speedup, slow down and rotate in both counterclockwise direction and clockwise direction.