Two-Degree-of-Freedom WPT System Using Cylindrical-Joint Structure for Applications With Movable Parts

• Published in: IEEE transactions on circuits and systems. II, Express briefs Express briefs, 2021-01, Vol.68 (1), p.366-370
• Main Authors: Houran, Mohamad Abou, Yang, Xu, Chen, Wenjie
• Format: Article
• Language: English
• Subjects: Circuits and systems; Coils; Couplings; cylindrical joint; Degrees of freedom; Inductance; magnetic coupling; motion-free structure; Robots; rotation-free structure; Three-dimensional displays; Winding; Windings; Wireless power transfer; Wireless power transmission
• ISSN: 1549-7747; 1558-3791
• DOI: 10.1109/TCSII.2020.2995616

A new winding structure for wireless power transfer (WPT) systems is proposed. The transmitter (Tx) and receiver (Rx) coils are wound on a semicylindrical and cylindrical structures, respectively. Thus, the Rx coil has two degree-of-freedom (2-DoF) movements. The first is linear ({\Delta } ) movement along the axial direction of the joint. The second is angular ({\alpha } ) movement around the axial direction of the joint, while transferring power. Winding methods and design procedures are discussed in detail. A prototype was built to validate the proposed idea. Experiment results have confirmed that the proposed structure achieved a constant power transfer efficiency (PTE) under linear movement. In addition, the Rx coil rotated up to 85° and maintained low variations of the efficiency, where PTE decreased by 4.61% for rotation between 0° and 85°. Moreover, the proposed WPT coils maintained a constant PTE under dynamic conditions. The proposed winding structure could be a good technique for applications that require linear and angular movements.