This paper proposes a 300 kW 24-slot/10-pole 6-phase stator-shifted fractional-slot concentrated winding spoke-type ferrite permanent magnet machine for electric truck applications. The proposed motor consists of a stator with dual three-phase windings positioned 75 degrees apart to reduce higher-order MMF harmonic order, and a rotor with an inexpensive and high-resistance ferrite permanent magnet in the spoke configuration. The simulated result of the stator-shifted machine is compared with a fabricated stator-shifted machine, and the results show good agreement with each other. To further reduce the torque ripple from 2.5 to 0.9% while maintaining a high maximum torque of 2980 Nm, circular voids with a diameter of 11 mm are embedded in the rotor. The proposed motor is evaluated for irreversible demagnetization, mechanical and thermal stability, and fault tolerant ability. To assess the proposed motor performance, the electric truck simulation model is constructed using MATLAB/Simulink and used to compare with the reported 12-slot/10-pole rare-earth permanent magnet-based machine. Compared to a previously reported six-phase rare-earth permanent magnet based flat-type machine, the proposed motor can save 4.3 kWh of energy with a USD 2512 lower cost while retaining a similar motor performance.
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The Effect of the Ratio of Remanent Flux Density to Coercivity of Magnet on Spoke-Type Permanent Magnet Synchronous Motor (PMSM) Performance
Spoke-type PMSMs were designed with
commercial permanent magnets and theoretically designed
hexaferrite: Nd-Fe-B (NdFe35, G1NH), Alnico (8B, 8H, 9),
and La-CoSrM hexaferrite (NMF-15G). It was found that
coercivity (Hc) plays a crucial role in determining motor
performance. The ANSYS Maxwell software was used to
characterize the designed motor performance. Commercial
RE-free Alnico 9 holds a 10.5 MGOe of (BH)max, much higher
than a 5.5 MGOe of RE-free Alnico 8B/8H and SrM
(SrFe12O19) hexaferrite magnets. However, the Alnico 9
motor performance is not better than the other Alnico 8B/8H
and hexaferrite motors. The spoke-type PMSM with our
theoretically designed SrM hexaferrite simulated motor
performance. A motor performs best when the Hc/Br ratio
equals one with a high Hc. For instance, the motor torque and
peak power increase to 189 Nm and 178 kW, respectively, as
the Hc increases to 4.86 kOe from 2.43 kOe. However, the
motor performance is not significantly changed with a fixed
Hc and various Br. It was found that regardless of (BH)max,
coercivity (Hc) plays a dominant role in motor performance.
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- Award ID(s):
- 1650564
- PAR ID:
- 10465584
- Date Published:
- Journal Name:
- 2023 11th International Conference on Power Electronics and ECCE Asia (ICPE 2023 - ECCE Asia)
- Page Range / eLocation ID:
- 39 to 44
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.23919/ICPE2023-ECCEAsia54778.2023.10213961
