Speed Ripple Reduction of Direct-Drive PMSM Servo System at Low-Speed Operation Using Virtual Cogging Torque Control Method

Bu, Feifei; Yang, Zhida; Gao, Yu; Pan, Zihao; Pu, Tianyu; Degano, Michele; Gerada, Chris

Abstract

This paper presents a virtual cogging torque (VCT) control method to reduce the speed ripple of direct-drive permanent magnet synchronous machine (DD-PMSM) servo system under low-speed conditions. Compared with other factors, at low speeds, the cogging torque is the main factor that deteriorates the drive performance, even induces speed oscillations. Especially in this paper, due to volume limitation, the cogging torque is designed larger than normal one in order to remove the need of brake. Based on the model of PMSM, the cause and effect of the cogging torque are analyzed. Inspired by the characteristic of cogging torque, the VCT control method is proposed and investigated to significantly reduce the speed ripple at low speeds. The main idea of this proposed control method is to produce a proper virtual cogging torque and continuously move the corresponding virtual stable equilibrium point to drive the rotor smoothly. In addition to the principle of this control method, its analysis and implementation are studied as well. Simulation and experimental results from the prototype demonstrate that the proposed control method is correct and valid, and it is simple and effective to smooth the speed at low-speed operations.

Citation

Bu, F., Yang, Z., Gao, Y., Pan, Z., Pu, T., Degano, M., & Gerada, C. (2021). Speed Ripple Reduction of Direct-Drive PMSM Servo System at Low-Speed Operation Using Virtual Cogging Torque Control Method. IEEE Transactions on Industrial Electronics, 68(1), 160-174. https://doi.org/10.1109/tie.2019.2962400

• Journal Article Type: Article
• Acceptance Date: Dec 6, 2019
• Online Publication Date: Jan 3, 2020
• Publication Date: 2021-01
• Deposit Date: Feb 6, 2020
• Publicly Available Date: Feb 6, 2020
• Journal: IEEE Transactions on Industrial Electronics
• Print ISSN: 0278-0046
• Electronic ISSN: 1557-9948
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 68
• Issue: 1
• Pages: 160-174
• DOI: https://doi.org/10.1109/tie.2019.2962400
• Keywords: Direct-drive servo system, Permanent magnet synchronous machine, Virtual cogging torque, Low speed, Speed ripple
• Public URL: https://nottingham-repository.worktribe.com/output/3908805
• Publisher URL: https://ieeexplore.ieee.org/abstract/document/8949446
• Additional Information: © 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, 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 component of this work in other works.