Effect of angle displacements on electromagnetic performance of dual three-phase consequent-pole permanent magnet machine

• Published in: IET electric power applications Vol. 14; no. 7; pp. 1177 - 1185
• Main Authors: Li, Feng, Wang, Kai, Zhang, Jianya, Zeng, Fanquan
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 01.07.2020
• Subjects: 24‐slot 22‐pole prototype machine; air gaps; angle displacement effect; asymmetric air‐gap flux density; back‐EMF waveforms; braking; braking torque; consequent pole rotor; CP rotor; demagnetisation; dual three‐phase consequent‐pole permanent magnet machine; electric potential; electromagnetic characteristics; electromagnetic performance; even‐order back electromotive force harmonics; fault conditions; healthy conditions; N poles; permanent magnet machines; PM demagnetisation; PM machine; Research Article; rotors; S poles; salient rotor iron; short circuit current; short‐circuit currents; static torque measurement; torque measurement; torque performance; unbalanced magnetic force; utilisation ratio; utilisation ratio; unbalanced magnetic force; consequent pole rotor; electromagnetic performance; salient rotor iron; short circuit current; fault conditions; short-circuit currents; torque performance; electromagnetic characteristics; air gaps; PM demagnetisation; braking torque; braking; back-EMF waveforms; torque measurement; rotors; demagnetisation; asymmetric air-gap flux density; 24-slot 22-pole prototype machine; dual three-phase consequent-pole permanent magnet machine; static torque measurement; electric potential; angle displacement effect; CP rotor; S poles; healthy conditions; even-order back electromotive force harmonics; N poles; permanent magnet machines; PM machine
• ISSN: 1751-8660; 1751-8679; 1751-8679
• DOI: 10.1049/iet-epa.2019.0611

The machine with consequent pole (CP) rotor can improve the utilisation ratio of permanent magnet (PM). However, all the N poles or S poles are replaced by salient rotor iron, leading to the asymmetric air-gap flux density. It potentially results in even-order back electromotive force (back-EMF) harmonics and unbalanced magnetic force. This study aims to investigate the influence of various angle displacements (i.e. 0°, 15°, 30° and 60°) on the electromagnetic performance of the dual three-phase PM machine with CP rotor. The electromagnetic characteristics, including air-gap flux density, back-EMF, torque performance, short circuit current, braking torque and PM demagnetisation under both healthy and fault conditions are compared comprehensively. Finally, the 24-slot/22-pole prototype machine is manufactured. The back-EMF waveforms and static torque are measured and compared to the finite-element predicted results to validate the theoretical analysis.