Indirect FOC System Research Of Asynchronous Motor

With the dramatic development of the electrical transmission theory, the ac speed regulation system, especially it of asynchronous motor has been getting increasingly significant. Because of high control accuracy, good low frequency characteristics, fast dynamic response and obvious advantages of decoupling effect, vector control technology occupies an important position in the field of ac speed regulation. This paper mainly adopts rotor field orientation vector system to control the performance of asynchronous motor.On the basis of referring to a large number of Chinese and foreign literature, asynchronous motor speed control methods are described briefly. The purpose is to draw out vector control technology, focusing on vector control technology based on rotor field orientation. At the beginning of the paper, perform the simple analysis about the mathematical model of asynchronous motor. According to the principle of coordinate changes, this paper lists on the mathematical model of asynchronous motor under common axis. Secondly, space vector pulse width modulation was introduced in detail, for the preparation for the implementation of vector control speed regulation system.This paper emphasizes on the rotor indirect field orientation vector control strategy, utilizing indirect field orientation vector regulates asynchronous motor speed. This paper introduces the basic principle of indirect field orientation and the decoupling method of stator voltage. The system preset the rotor flux linkage reference value, measures the motor speed. The slip frequency decides the toque, which forms slip vector control. Then it sets up and simulates function modules under MATLAB/SIMULINK. Analyze the simulation results in detail, and prove the feasibility of the control system.For the realization of the asynchronous motor indirect field orientation control system, this paper builds physical hardware platform consisted of dsPIC33FJ128MC706A digital signal controller as the core control chip, intelligent power module IPM as switching device. And this paper designs relevant control circuits, for example, zero point detecting circuit, speed detecting circuit, current detecting circuit. Software programs is compiled and debugged in the MPLAB IDE development environment. This paper introduced the interrupt service subroutine, variable voltage variable frequency of speed regulation method, M/T measurement of motor speed, and the algorithm of PI regulator in detail. Finally, get the expected results.