Phase Current Reconstruction for DTP-PMSM With Single Current Sensor Using Synchronous Filtering Reconstruction Method

In dual three-phase permanent magnet synchronous motor (DTP-PMSM) drive, six-phase current information is critical to motor control. However, the adoption of multiple current sensors increases the size and cost of inverters. To mitigate this issue, this article proposes a method to reconstruct six-phase currents of a DTP-PMSM by using a single current sensor (SCS). First, the SCS is repositioned to a current branch. Then, sampling is performed twice in one period based on the switching state of a single bridge arm. Therefore, two orthogonal phase currents are achieved. Furthermore, the synchronous filtering reconstruction method is proposed. Through this method, the harmonic current information is extracted from two orthogonal currents and the remaining four-phase currents are reconstructed. Overall, six-phase currents can be accurately reconstructed by using an SCS, for which the hardware cost and inverter size can be reduced. The proposed method is validated by both simulation and experiments.