Dynamic modeling of losses in electrical machines for active loss control

This paper presents a dynamic core loss model for active loss control of permanent magnet synchronous machines. Deadbeat-direct torque and flux control (DB-DTFC) enables direct control of torque and stator flux linkage over each switching period. Total machine loss can be minimized by selecting the optimal flux level in every sampled time instant. Reliable models for dynamic copper and core loss are an essential requirement for this optimizing task. This paper presents an analytical dynamic core loss model in switching period time-domain, using stator flux linkage as the manipulated input variable. Combining numerical and analytical calculation methods is used to create an easy and practical approach to estimate core loss components based on stator flux linkage without running FEA calculations for every time instant. Additional effects like high frequency eddy current loss in electrically conducting permanent magnets as well as spatial harmonic content are taken into account.