Characterization of Iron Loss for Integral-Slot Interior Permanent Magnet Synchronous Machine During Flux Weakening

Iron loss resistance is widely used for rapid motor design and maximum efficiency control. However, the harmonic loss obviously increases during flux weakening, and even dominates in total iron loss, especially in deep flux weakening region. This paper presents an analytical calculation method of iron loss for an integral-slot interior permanent magnet synchronous machine (IPMSM) by iron loss resistance, considering harmonic effect during flux weakening. To predict the harmonic loss, both a harmonic loss voltage and a harmonic loss coefficient are employed into an iron loss resistance model, and the relation of harmonic loss to the harmonic voltage and coefficient are studied. The iron loss and efficiency of an integral-slot IPMSM are, respectively, obtained by the proposed model, the conventional model, the experiment, and finite-element analysis (FEA). The proposed model is validated by the comparison with FEA and experimental results.