A fractional slot multiphase air-core compulsator with concentrated winding

Zhao, Weiduo; Wu, Shaopeng; Cui, Shumei; Gerada, Christopher; Zhang, He; Xu, Zhuang

Abstract

Compulsator is a specially designed generator capa¬ble of delivering high current pulses to a low-impedance load, such as the electromagnetic railgun. In order to increase the tip speed of the rotor, advanced composite materials have been used in the recent compulsator prototype, which is mentioned as air core instead of the traditional iron core. For typical air-core compulsators, there are no slots and steel teeth to place the armature windings due to the nonmachinability of composite materials. Therefore, concentric windings in racetrack style are often adopted instead of traditional lap winding in most cases, since it is more convenient to be fixed by composite materials. However, overlap occurs at the end winding part for multiphase compulsators, which are not easy to be formed during the manufacture process. In this paper, a fractional slot multiphase air-core compulsator with concentrated windings is proposed and analyzed. The main advantage of fractional slot configuration is that it can offer a concentrated winding structure under certain conditions, which means each coil only spans one “tooth,” and will not cause any intersection between each phase at the end winding. Two referenced fractional slot air-core compulsators with two phases, six poles, and four “slots” or eight “slots” (q = 1/3 and q = 2/3, q is the “slot” per pole per phase) are analyzed and compared with the performance of a traditional integral slot machine. The results indicated that the output voltage and self-excitation performance of a fractional slot compulsator can reach the same level with an integral slot one, and the discharging performance can reach an acceptable level. Thus, the fractional slot multiphase concept can be further used to improve the manufacture process of the winding in the future.

Citation

Zhao, W., Wu, S., Cui, S., Gerada, C., Zhang, H., & Xu, Z. (2017). A fractional slot multiphase air-core compulsator with concentrated winding. IEEE Transactions on Plasma Science, 45(7), 1387-1393. https://doi.org/10.1109/TPS.2017.2705243

• Journal Article Type: Article
• Acceptance Date: May 13, 2017
• Publication Date: May 23, 2017
• Deposit Date: Jun 30, 2017
• Publicly Available Date: Jun 30, 2017
• Journal: IEEE Transactions on Plasma Science
• Print ISSN: 0093-3813
• Electronic ISSN: 1939-9375
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 45
• Issue: 7
• Pages: 1387-1393
• DOI: https://doi.org/10.1109/TPS.2017.2705243
• Keywords: Compulsators, electromagnetic launch, frac¬tional slot windings, multiphase, railguns
• Public URL: https://nottingham-repository.worktribe.com/output/861849
• Publisher URL: http://ieeexplore.ieee.org/document/7932892/
• Additional Information: 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.
• Contract Date: Jun 30, 2017