LAUSR

This study presents a novel phase current reconstruction strategy for switched reluctance machines (SRMs) using two cross-winding current sensors. The phase currents are reconstructed by solving the linear equations associated with two adjacent phase currents in the different turn-on regions. The effect of current sensor offset and power transistor fault on the proposed reconstruction method is analysed. On the basis of the current difference at the rising edge of each drive signal, an offset sensor identification method is presented and two online compensation schemes are adopted. For power transistor short-circuit fault, the logic-judgment-based and freewheeling-time-based diagnostic methods are investigated and a virtual current sensor is introduced to ensure the effectiveness of the reconstruction process. The proposed phase current reconstruction strategy is free from power transistor open-circuit fault. In addition, the current reconstruction method is easily extended to SRMs with higher number of phases without additional current sensors. Simulations and experiments validate the effectiveness and flexibility of the proposed reconstruction strategy.