A novel direct torque control system based on space vector PWM

A novel direct torque control method is presented in this paper. The flux error and torque error produce a decoupled stator voltage reference vector by means of the PI regulator. The reference vector is converted to a voltage vector, which is based on stator coordinates reference frame from coordinates transformation. The switch control signal of the inverter is finally produced through space vector pulse width modulation of the preceding voltage vector. The novel control method has been applied to the variable-speed system of an asynchronous motor. It was easily realized in the form of digitization with DSP of TMS320FL2407, and has got low torque pulsation, less current harmonic, constant switch frequency with this control method. The experimental results indicate that the variable-speed control system has got both fine dynamic performance and high accuracy of the entire speed region.