A new dead-time compensation method on direct torque control system based on DSP

In direct torque control, the voltage source inverter (VSI) was controlled based on Space-vector pulse width modulation (SVPWM). The SVPWM is an excellent control strategy, but the relation between reference voltage and actual output voltage is nonlinear due to the dead time effect and the voltage drop of power devices. The distortion of voltage invokes serious problems such as current waveform distortion and deterioration of the systems. An improved method which reduces the distortion of voltage and current in induction motor direct torque control (DTC) system is presented. It compensated three-phase voltages in terms of current directions. The method can be implemented with software without any extra hardware. The experiment results verify this method has a good compensation effect.