Steady-State Efficiency Optimization Method for PMSM Considering Current Distribution and Iron Loss Resistance

Conventional control strategy for permanent magnet synchronous machine (PMSM) has the defect of low steady-state efficiency as a result of ignoring iron loss resistance and unreasonable current distribution. In this brief, a steady-state efficiency improvement method considering the current distribution coefficient and iron loss resistance is proposed. Firstly, iron loss resistance is incorporated into equivalent circuit and mathematical model of the PMSM in d-q rotating coordinate frame. Secondly, steady-state reference current components of the d-axis and q-axis are analytically calculated by current distribution coefficients, two computational models that can accurately predict iron loss resistance under the condition of known and unknown hysteresis and eddy current loss parameters are derived and proposed for the first time. Finally, experimental comparison with conventional methods such as $i_{\mathrm { d}}{=}0$ and MTPA proves validity and superiority for our proposed method.