Three-Phase Asynchronous Motor Vector Control Design And Implementation

Three phase asynchronous motor has the advantages of simple structure, reliable operation, light weight and cheap price, so it has been widely used, but its speed regulation is difficult to limit the wide use of asynchronous motor. At present, with the development of power electronic devices, AC frequency control technology is gradually mature, and the vector control technology has been widely used in the field of AC speed regulation after decades of continuous development. The design and implementation of the system based on Microchip series DSC design of three-phase asynchronous motor vector control system. The main content is based on the principle of vector control, digital signal processor dsPIC30F4011 chip as the control core, a DSP based three-phase asynchronous motor indirect vector control system is constructed. The principle of coordinate transformation to the three-phase stator current is decomposed into electromagnetic current and torque current, then based on the mathematical model of the three-phase asynchronous motor, the calculated rotor flux, flux angle, electromagnetic torque and other parameters, and then the standard PI control loop of these parameters are controlled separately, so as to realize the decoupling control of flux and torque.(1) The voltage, flux and torque equations of three-phase asynchronous motor in three-phase static coordinate system are studied. Using Clake transform and Park transform, the flux equation, electromagnetic torque equation and slip angle velocity equation of the motor in the two-phase rotating coordinate system are derived. In addition, the principle and implementation method of space voltage vector modulation technology are also studied.(2) Constructing a system diagram of three-phase asynchronous motor vector control, the main part of the system of the motor running parameter measurement module, coordinate transformation module, flux observer module, torque observer module, PI controller module, pulse generator module, inverter module. Then build these modules in MATLAB, connect to the system and simulation. From the simulation results, the speed regulation time and the steady state error of the control system are obtained, as well as the size of the stator three-phase current, the fluctuation of thetorque and so on.(3) The control board is designed with digital signal processor dsPIC30F4011 chip as the control core. The whole system consists of the minimum system circuit, the serial port circuit, the current signal processing circuit and the power supply circuit.The intelligent power module(IPM) PS21963 chip to design the motor driver board to drive the core, the whole system consists of optocoupler isolation circuit, inverter circuit, power supply circuit implementation. Altium in the drawing of the schematic,and design and production of the PCB board, a three-phase asynchronous motor speed control system hardware.