Improved model‐predictive‐flux‐control strategy for three‐phase four‐switch inverter‐fed flux‐reversal permanent magnet machine drives

In this study, an improved model‐predictive‐flux‐control (MPFC) is developed and implemented based on a three‐phase flux‐reversal permanent magnet (FRPM) machine drives fed by three‐phase four‐switch voltage‐source‐inverter (TPFS‐VSI) with fewer switches and lower costs. The voltage variations and offsets across the two DC‐link capacitors in this kind of inverter topology are suppressed by deriving an analytical expression of the DC‐link capacitor voltages to reveal the inherent relationship between capacitor voltages and phase currents. In addition, the calculation process of the stator flux‐linkage vector reference is simplified by adopting the dq ‐axes frame, and consequently, a precise predictive model is constructed for the stator flux‐linkage vector control. Then, both the steady and dynamic performances of the TPFS‐VSI‐fed FRPM machine under the developed MPFC are evaluated by simulations and experiments. Meanwhile, the inverter and machine losses of the FRPM machine driven system of TPFS‐ and TPSS‐VSI are measured for efficiency evaluation. The simulated and experimental results indicate that the developed MPFC not only offers the convergence of the DC‐link voltages fed by the TPFS‐VSI, but also improves the performance of the TPFS‐VSI‐fed FRPM machine drive in the low to medium speed applications.