Research On Speed Sensorless Vector Control Of Induction Motor

With the dramatic development of electronic technology and computer science,the speed regulation technology of alternating current machine based on them has made considerable progress. the application of field-oriented technique,the speed control of ACIM (Alternating Current Induction Motor)is becoming a good competitor of traditional DC(Direct Current)motor speed control system in the aspects of speed control and torque control. By eliminating speed sensor,the sensor-less control system of ACIM is supposed to be simpler and rugged,and accordingly is becoming a hot research subject recently.The dissertation takes the drive system of asynchronous motor for the research object,takes vector control for the control mode,takes MRAS as the control arthmetic,takes TMS320F2407DSP for control core and designs the entire asynchronous motor sensor-less control system.The principle and realization method of vector control and SVPWM(space vector pulse width modulation)have been analyzed.For vector control the analysis of induction motor mathematic models and control equations under three-phase static coordinate system,two-phase static coordinate system and circular coordinate system is presented in the dissertation,and then the control equation under synchronous circular coordinate system based on rotor field orientation is acquired.The principle,control algorithm and realization method by DSP of SVPWM are also given,and then designed the vector control system of induction motor.The system adopted TMS320F2407 as control core, Ins ulated Gate Bipolar Transistor (IGBT)to constitute the main power loop to form a two loop-locked control system by detecting currents and rotor speed. At the sametime to complete the software of the design. In the end,the system emulate modulations are constituted on the Matlab/Simulink.It completed the establishment of the control system simulation module and the simulation based on the basic principles of vector control system.From the simulation result,the eurrent and speed of asynchronous motor has a better dynamie character and static character and can satisfy the request of the motor stable movement.Making use of the DSP with high-speed capability,the fully digital vector control for induction motor is implemented,and some experiment results are given.The results show that the speed sensorless vector control system for induction motor based on DSP has better dynamic and static character.