Time Efficient Calculation of Current Harmonics in Inverter-Fed Permanent Magnet Excited Synchronous Machines

The prediction of the time-slope of the phase currents in a permanent magnet excited synchronous machine (PMSM) fed from an inverter are often carried out using models of transient co-simulation of time stepping finite element method (FEM). These are based on the differential equations for PMSM with saturation-dependent parameters identified from FEM and are slow and computationally expensive. This paper presents a fast and time efficient methodology that allows these currents to be calculated in a fraction of the time. Additionally, it is no longer necessary to use special software; the equations used can be implemented in any programming language.A comparison with one of the already frequently validated transient co-simulation models for a PMSM proves the applicability of the methodology and at the same time shows which potentials the methodology has to be extended.