| In asynchronous motor s frequency controlled system, in order to realize the speed closed-loop control, the shaft s speed information is an essential point. Since traditional V/f (Frequency conversion adjustment voltage) technology can't control the torque efficiently, the precision, carrying ability, and response are all reduced. So this engine only can be used in an environment where high timing performance is not needed. While the algorithm for vector control can solve all these problems with controls on magnetic flow and torque. If we install a velocity sensor on the engine s shaft, it will not only bring additional limits in working condition and exploitation condition, but reduces the reliability to a certain extent. Theoretically calculate the rotate speed dynamically through its electricity can take out the speed sensor, it can reduce the size of axial direction as well as the system cost, and enhance the ability of anti-jamming and reliability. So after skip 2 speed sensors, how to control the speed in a high precision with electricity, while it can meet the requirement and reduce the cost is the key direction in this research.Starting with vector-controlled theory, based on rotor magnetic field-oriented fundamental and the flux linkage voltage equations of the induction motor deduced under the synchronous reference frame, this paper propose a kind of vector-controlled approach based on the rotor magnetic-field orientation control, wherein error signal of the stator q-axis current in the synchronous reference frame is utilized to evaluate the speed value of the induction motor and SVPWM method is adopted in velocity modulating control of the induction motor. This paper completes the speed, flux, and torque designed and controlled both in hardware and software by DSP core board. Finally, the result of the experimentation demonstrates that the proposed vector control system has good dynamic and static performance, which has achieved the satisfying effect.
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