TY - GEN
T1 - Permanent magnet reduction by current harmonics injection for surface permanent magnet machines
AU - De Gaetano, Daniele
AU - Sala, Giacomo
AU - Degano, Michele
AU - Gerada, Chris
N1 - Publisher Copyright:
© 2021 IEEE.
PY - 2021/4/8
Y1 - 2021/4/8
N2 - This paper presents the analysis of multi-harmonic current injection in multi-three phase surface permanent magnet (SPM) machines. An analytical model, extended to a generic harmonic order, is used to describe and determine the no load flux density, the back electromotive force (BEMF) and the electromagnetic torque produced. These are analysed as a function of the permanent magnet span. Based on the BEMF, the harmonics injection technique is adopted to increase the torque in the machine, while keeping the RMS current constant, thus without affecting the Joule losses. In order to understand how the torque is affected by the harmonics injection, considering different PMs rotor span, a comparison with and without injection is presented. It is shown how, thanks to specific harmonics injection, it is possible to reduce the permanent magnet content in SPM machines while generating the same torque performance of a motor with higher PM content, without harmonic injection. The analytical results are finally validated by means of Finite Element Analysis (FEA) considering two different PM rotor span, as a case study, highlighting the benefits of the proposed method.
AB - This paper presents the analysis of multi-harmonic current injection in multi-three phase surface permanent magnet (SPM) machines. An analytical model, extended to a generic harmonic order, is used to describe and determine the no load flux density, the back electromotive force (BEMF) and the electromagnetic torque produced. These are analysed as a function of the permanent magnet span. Based on the BEMF, the harmonics injection technique is adopted to increase the torque in the machine, while keeping the RMS current constant, thus without affecting the Joule losses. In order to understand how the torque is affected by the harmonics injection, considering different PMs rotor span, a comparison with and without injection is presented. It is shown how, thanks to specific harmonics injection, it is possible to reduce the permanent magnet content in SPM machines while generating the same torque performance of a motor with higher PM content, without harmonic injection. The analytical results are finally validated by means of Finite Element Analysis (FEA) considering two different PM rotor span, as a case study, highlighting the benefits of the proposed method.
KW - Analytical models
KW - Electric machines
KW - Harmonic injection
KW - Magnetic flux density
KW - Multiphase machines
KW - Permanent magnet machines
KW - Rotating machines
UR - http://www.scopus.com/inward/record.url?scp=85106626395&partnerID=8YFLogxK
U2 - 10.1109/WEMDCD51469.2021.9425662
DO - 10.1109/WEMDCD51469.2021.9425662
M3 - Conference contribution
AN - SCOPUS:85106626395
T3 - Proceedings - 2021 IEEE Workshop on Electrical Machines Design, Control and Diagnosis, WEMDCD 2021
SP - 137
EP - 142
BT - Proceedings - 2021 IEEE Workshop on Electrical Machines Design, Control and Diagnosis, WEMDCD 2021
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2021 IEEE Workshop on Electrical Machines Design, Control and Diagnosis, WEMDCD 2021
Y2 - 8 April 2021 through 9 April 2021
ER -