Modelling of anisotropic synchronous machine in stator reference frame

Interior permanent magnet-synchronous machines (IPMSM) feature many favourable properties for e-mobility application as high power density and good efficiency. However, they require careful modelling because of strong anisotropies of the rotor, as they are also known from salient-pole synchronous machines. These anisotropies are often accounted for by different values for the d-axis and q-axis inductances in a rotor-flux-oriented coordinate system. With regard to asynchonous machine control, stator-flux-oriented control could provide improved dynamic behaviour - especially in the field-weakening range. The representation of fault conditions inside the machine, leading to asymmetrical machine parameters, suggests a phase-wise description instead of the usual two-axis (d-q or space-vector) analysis. This paper presents a machine model which provides a basis for stator-flux-oriented control and for the simulation of fault conditions inside the machine. This is reached by a phase-wise representation based on the known approach using rotor-flux-oriented d-axis and q-axis inductances. A physical interpretation for self and mutual inductances is given. A single-phase winding interruption fault is simulated to outline the capability of the chosen approach.