Space-vector State Dynamic Model of the Synchronous Reluctance Motor Considering Self, Cross-Saturation and Iron Losses

Abstract

This paper proposes a space-vector dynamic model of the Synchronous Reluctance Motor (SynRM) including both self-saturation, cross-saturation effects, and iron losses expressed in state form, where the magnetizing current has been selected as a state variable. The proposed dynamic model is based on an original function between the stator flux and the magnetizing current components, improving a previously developed magnetic model. Additionally, the proposed model includes, besides the magnetic saturation, also iron losses. The proposed model requires 11 coefficients, among which 6 describe the self-saturation on both axes and 5 describe the cross-saturation. Starting from the definition of a proper co-energy variation function, both the static and dynamic inductances expressions have been analytically developed, so that the reciprocity condition for the cross-saturation is satisfied. This paper presents also a technique for the estimation of the parameters of the magnetic model and also the resistance describing the iron losses. This technique is based on the minimization of a suitably defined error function which includes the difference between the measured and estimated fluxes. The proposed parameter estimation technique has been tested in both numerical simulation and experimentally on a suitably developed test set-up and the proposed model has been thus validated experimentally