Svpwm Variable Frequency Speed Control System For Ac Induction Motor

In this paper, the method of AC motor speed regulation was discussed and the development of variable-frequency-speed-regulation technology was displayed. With advantages such as higher usage of DC voltage, adapt to digital-control, the capacity of building high performance speed regulation system, et al., Space-Vector-Pulse-Width-Modulation(SVPWM) is a better method than Sinusoidal Pulse Width Modulation in field of AC motor speed regulation. Under the light of simulating AC ansynchronization-motor as DC motor, frequency conversion technology with vector-control depends on completely research of ansynchronization-motor's mathematic model. So, the ansynchronization-motor's mathematic model was analyzed and the model was treated with orthogonal transform. From the transform, a new mathematic model in 2-phase-rotation-coordinates with synchronous speed appears and the stator current is synthesized by two components: one is the torque component, the other is the flux component. By controlling the two current, AC motor can be controlled like a DC machine which torque and field can be adjusted respectively. In this paper, a inbuilt system was investigated and analyzed to realize the SVPWM slid frequency system, as while as the voltage-vector-output-configuration of the inverter and the Space Vector Modulation(SVM) scheme and the measurements of rotor-flux were studied. The system hardwares, include power circuitry topology and control/drive board and speed&stator current detective circuitry and so on, were researched. The system software which makes up of vector transforming, SVM, PWM wave output, speed adjustment with digital PI adjuster and current signal processing was designed, too. System simulations and experiments were given to test the research. In the MATLAB/SIMULINK environment, modules of AC ansynchronization motor and vector transforming and SVM were built.