Enhanced Mathematical Modelling of Interior Permanent Magnet Synchronous Machine Considering Saturation, Cross-Coupling and Spatial Harmonics effects

Abstract

The Interior Permanent Magnet Synchronous machine (IPMSM) conventional mathematical model is generally employed to investigate and simulate the IPMSM control and drive system behaviour. However, magnetic nonlinearities and spatial harmonics have a substantial influence on the IPMSM electromagnetic behaviour and performances. In order to simulate the IPMSM real electromagnetic behaviour, this paper describes an enhanced mathematical model that takes into account the saturation, cross-coupling and spatial harmonics effects. This model has been implemented in Matlab ® /Simulink environment where the electric and magnetic parameters are derived from FEA investigations and implemented by the use of lookup tables. The high fidelity of the proposed IPMSM Simulink model is validated by the results of the FEA investigations carried out.

Impact Evaluation of Innovative Selective Harmonic Mitigation Algorithm for Cascaded H-Bridge Inverter on IPMSM Drive Application

“…6-8. Compared to the results reported in [46], it is possible to detect a more accurate fidelity of the proposed enhanced mathematical model of IPMSM with respect to FEM results. Therefore, the proposed IPMSM enhanced mathematical model can be used to investigate the electromagnetic behavior of the IPMSM, especially in terms of efficiency and torque ripple and thus also the effectiveness of the new harmonic mitigation algorithm used to control the CHBMI.…”

“…In this study, an enhanced mathematical model of IPMSM, that considers saturation, cross-coupling, spatial harmonics, and iron loss effects, has been employed. In detail, the proposed mathematical model of IPMSM is defined starting from a previous study [46] where a mathematical model of IPMSM considering the saturation, cross-coupling, and spatial harmonics effects are described and discussed. This modelling approach is based on the definition of dq-axes flux linkage λd, λq as a function of dq-axes current components id, iq, and mechanical position θm.…”

“…where vd, vq are the dq-axes voltage components, id, iq are the dq-axes current components, ωm is the mechanical angular speed, ωe is the electrical angular speed, λdPM, λqPM are the dqaxes permanent magnet flux linkages, Lii inc and Lij inc represent the self and mutual incremental inductances components, Ld app and Lq app are the dq-axes non-coupled apparent inductances that including both self and cross-saturation effects [45]- [46]. Generally, the flux linkage λqPM can be neglected since it presents a very low value.…”

“…Negative values of the q-axis current iq are not considered because only motor operations have been investigated. The derived electromagnetic quantities are shown and discussed in [46]. Furthermore, several transient simulations have been performed to determine the quantities necessary for the definition of the iron loss model.…”

“…In detail, a field-oriented control strategy has been adopted to drive the proposed IPMSM enhanced mathematical model for each working point of interest and the current waveforms are extracted and used as input quantities in the current FE model at the same speed condition. In order to appreciate the benefits deriving by the proposed enhanced mathematical model of IPMSM, the same operating point analyzed in [46] has been considered, where the IPMSM operates at 4000 rpm, 2.31 Nm, and dand q-axis current mean values equal to -3 A and 5 A. The comparison between the electromagnetic torque waveforms and the input dq-axes voltages waveforms predicted with the proposed Simulink model and the FE model are reported in Figs.…”