The Research On Speed Sensorless Vector Control System For Induction Motor Based On FPGA

The rapid development of computer control technology and the mature of electronic technology, provide a theoretical and practical basis for the development of the AC induction motor speed control system. Meanwhile, AC induction motor speed control systems also tend to digitize. Induction motor is widely used in AC drive system because of the prominent advantages of simple structure, reliable operation and easy manufacturing. In order to overcome the shortcomings that speed sensor brings in high-performance AC induction motor speed control system, researching on the speed sensor-less control technique has broad prospect and practical significance. With the popularization and development of FPGA devices, complex control algorithm could be implemented with FPGA.This thesis mainly designs a set of induction motor speed sensor-less vector control system using FPGA as the control core. Firstly, the induction motor’s mathematical model under the stationary coordinate system and the rotating coordinate system is discussed in this thesis. The basic theory of the vector control, the basic structure of the rotor field oriented speed sensor-less control system based on SVPWM modulation are also analyzed. Secondly, through the analysis of induction motor’s mathematical model, this dissertation constructs MRAS to estimate rotor speed. By analyzing the MRAS using PI controller, this thesis designs a novel Sliding-Mode Model Reference Adaptive System based on approach law. This method has a better effect on chattering reduction and has robust ability to external noise disturbance. Furthermore, the simulation model of Induction motor speed sensor-less vector control system under the Matlab/Simulink is established, and the traditional MRAS and MRAS based on sliding mode control simulation results are compared, the results show that the MRAS based on sliding mode control has the advantages of good dynamic response and small steady-state error.Finally, the EP4CE10E22C8 of ALTERA Company is selected as the controller, the control system experimental platform is established, and the FPGA control circuit, driver circuit, detection circuit is designed. In the software section, using Verilog as the programming language, under the environment of QUARTUS II, coordinate transformation module, speed identification module, SVPWM module and digital PI module etc are designed and simulated in Modelsim. The speed sensor-less vector control system are conducted on the experimental platform, The results show the correctness that the estimated speed of MRAS based on sliding mode control, the control system has good performance.