Time-based current detection method with three shunt resistors in the 3-phase PWM inverter

This paper presents an improved method of determining voltage reference to detect currents in the three-phase inverter with three shunt resistors. In order to determine the voltage reference, the proposed method uses geometrical property in the voltage boundary hexagon of space vector PWM. The change of voltage reference is represented using time, which explains why the proposed method is called a time-based method. The proposed method decreases dramatically the computation time in a fixed-point DSP by eliminating a division operation which is the main cause of increasing the computation time in the conventional one. The proposed method is verified in the simulation and the experiment.