The Study Of Field-Weakening Control On AC Induction Motor

Based on indirect field-oriented control (IFOC) theory, the thesis mainly focuses on the study of field-weakening control on the digital AC induction motor driver system. The theory analysis of the induction motor operation model, simulation study of the control system, and experiment verification are done as the three main parts of the research.Firstly, based on the mathematic model of the induction motor, the working state of induction motor within wide speed scope is analyzed under the voltage limit and the current limit. Then using the indirect field-oriented control theory and analyzing the characteristics of different running area of motor, several important problems are studied to improving the torque and dynamic performance in the field weakening region, such as field-weakening control, PI regulator design, current vector decoupling, voltage limitation control and so on. Based on theory analysis, the control system simulation model is set-up using Matlab/Simulink,and these methods mentioned above is verified and a valid solution is taken. After that, the hardware platform, which based on the high performance motor controller TMS320C2812 and IPM PM50RLA120, is introduced. And the hardware architecture and function design are described. The DSP software task is scheduled as non-real-time control tasks based on cyclic calling mode and real-time control tasks driven by interrupt mode. The main program including interrupt procedures and the algorithm flow processes of main function modules are presented. Finally, the system simulation results and experimental results are analyzed relatively to verify the design. A proposal for further study is also put forward.