Enhanced Phase Current Reconstruction Strategy in Overmodulation Range for Single DC-Link Shunt PMSM Drives

To extend the modulation range of the single dc-link shunt based permanent magnet synchronous motor (PMSM) drive, a novel phase current reconstruction strategy is proposed in this paper. A current observer based on Luenberger structure is designed to estimate the unsampled phase current due to the limitation of the voltage vector shifting in the overmodulation range. The estimated current is applied to the reconstruction of three phase currents and closed-loop control. The experimental results show the effectiveness of the proposed method in different operation conditions.