LAUSR

In this article, a compact single current sensor measurement-based four-phase switched reluctance motor (SRM)-integrated drive system is developed. Based on the current measurement characteristics of this drive system, the phase current reconstruction and demagnetization current suppression strategies are proposed. To ensure reliable operation of the SRM, two key issues are considered: 1) the four-phase current should be obtained from the only measured bus current signal and 2) as the nonconducting phases are unable to demagnetize normally with traditional control algorithms, serious negative torque effects exist. For the first issue, a four-phase current reconstruction method is proposed by decoupling the adjacent two-phase currents in the overlapping conduction regions. For the second issue, high-frequency pulses are injected in the shared upper power switch of the bridge arm where the conducting phase is located, providing rapid demagnetization for the other phase in the same bridge arm. The two methods are fully decoupled and can be integrated freely to achieve current reconstruction and demagnetization of current suppression. Based on these methods, a hybrid control algorithm that can satisfy the operation requirement in different speed ranges is developed for the SRM drive. Experiments have been implemented in an 8/6 structure SRM prototype-based system, and detailed experimental results verify the effectiveness of the proposed methods.