Research On Vector Controlling Of The Induction Motor Based On Sliding-Mode Observer

The speed-sensorless vector control of induction motor is one of the hot topics in electric-drive field, whose main study is to adopt a kind of quick and effective method to accurately observe the rotor flux and rotor speed in the condition that the parameters vary when certain and uncertain disturbance exists.The development of speed-sensorless field-oriented controller method is based on with-speed-sensor field-oriented controller method. So firstly, the dissertation analyzes the mathematics model of induction motor, studies field orientated control (FOC) of induction motor and space vector pulse with modulation (SVPWM).Then, this dissertation presents a solution to the problem of accurate flux, and velocity estimation. In this research, a sliding mode based flux and speed estimation technique for speed sensorless control of field oriented induction machine is first investigated. The parameter sensitivity of the control method is also analyzed. The method is used to construct a simplified system for speed-sensorless vector control of induction motor. The effectiveness of the proposed observers is analyzed by simulation in this control system. Then an adaptive sliding mode observer is proposed and the stability is verified by Lyapunov theory and Popov criterion. Two sliding mode current observers are utilized to compensate the effects of parameter variation on the rotor flux estimation, which make flux estimation more accurate and insensitive to parameter variation. The effectiveness of the proposed observers is analyzed by simulation.The dissertation uses Digital Signal Processor (DSP) TMS320LF2407A special for digital motor control of TI Corporation as the control core, and develops the software and hardware of the full-digital induction motor vector control speed adjustment system. The main structures of the software and hardware parts of the speed adjustment system are introduced in the third part of this dissertation. Principles and realization of the main functional blocks of these two parts are also illuminated in this part. In the hardware system, the main circuit, control circuit and protective circuit are designed in detail in this paper. Based on the hardware circuit, the software is programmed by using assembly language and C language combined.The program is debugged on the designed software and hardware system .The results of experiment further demonstrates the reasonableness and superiority of the proposed design method.