Phase Current Sensing Method using Three Shunt Resistor for AC Motor Drive

This paper proposes a novel method for reconstructing three phase inverter phase currents using the information from shunt resistors. To control the instantaneous torque when controlling SVPWM to drive AC motor, the phase current information is essential. A method using shunt resistor is one of the phase current sensing methods needed to drive AC motors. One advantage of a phase current sensing method using shunt resistor is it is possible to configure the sensor part at comparatively lower cost than a sensing method using hall sensor. Sensing methods using shunt resistors include: a sensing method applying each shunt resistor to the bottom of three-phase inverter switch arm and a sensing method applying each shunt resistor to the bottom of DC-Link. This study defines the area where it is not possible to detect the current generated during the detection of phase current three-phase inverter, using the area where it is not possible to detect the current, and then verifies that through simulation.