Analysis of Phase-Shift Algorithm for Single-Shunt Current Sensing with Two-Arm Modulation

Single-Shunt Resistor is typically used to detect inverter currents due to the cost of electronics components or circuits. However, for an inverter implemented with Space Vector PWM, the single-shunt method cannot sense a current in some regions of the current waveforms that occur when one active switching state in a switching period has inadequate state time to use for measuring an inverter current. In case of three-arm modulation, Phase-Shift algorithm is represented to reduce this immeasurable problem by shifting the modulated signals of an inverter such that the active state has enough sensing time, and the three-phase current can be all detected. This paper is a study of phase-shift algorithm for single-shunt current sensing while using two-arm modulation and its condition, as well as the limitations occurred from this method.