Average Current Reconstruction using Carrier Phase Reversal Switching Technique in a 3-Phase Inverter with DC-Link Current Sensor

We propose a switching technique for the three-phase inverter system in this paper, using a single current sensor to reconstruct the average phase current. Typically, methods such as measurement voltage injection are widely used to avoid the unreconstructible current region. However, existing techniques have limitations in terms of reconstructing the average current, resulting in phase differences between the actual and the reconstructed currents. This limitation leads to a control performance degradation. Thus, in this paper, we present a method that uses phase variation of the switching carrier to extend the reconstructible current region. We propose a method that accurately measures the average current within the switching period by restoring one phase of the current per sampling instance. This approach enables a precise measurement of the average current within each switching cycle.