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Title Refurbishing three-phase synchronous reluctance machines to multiphase machines
ID_Doc 14047
Authors Tawfiq, KB; Ibrahim, MN; EL-Kholy, EE; Sergeant, P
Title Refurbishing three-phase synchronous reluctance machines to multiphase machines
Year 2021
Published Electrical Engineering, 103, 1
DOI 10.1007/s00202-020-01064-w
Abstract Refurbishing electrical machines to have a higher performance and/or reliability is a clear trend in the circular economy. This paper investigates the gain in efficiency, torque density and reliability with replacing the windings and the iron of the stator of existing three-phase synchronous reluctance machines (SynRMs), resulting in a multiphase machine. The stator housing, shaft, bearings and the rotor are not changed, to keep the cost of refurbishing low. As the housing and rotor are kept, logical constraints are to have the same inner and/or outer stator diameters, air gap length and axial length. In the new windings, an identical copper volume is considered as a constraint. An optimization technique is coupled to 2D finite element method to select the optimal slot dimensions. Case studies showed that it is possible to replace the stator of existing three-phase SynRMs with a better performance multiphase one. It is found that the average torque, efficiency and power factor of the five-phase SynRM are increased by 11.78%, 0.72% and 5.54%, respectively, compared to a three-phase SynRM at rated conditions. At higher speeds (three times rated value), the efficiency and average torque are greatly improved by about 3.64% and 33.67%, respectively, compared to the three-phase SynRM. Moreover, a faulty case of one phase opened is also investigated. The five-phase SynRM works at 75.45% of the healthy rated torque of the three-phase SynRM, whereas the three-phase SynRM works at only 43%. Measurements on an existing 5.5-kW, three-phase SynRM confirm the observed results.
Author Keywords FEM; Machine design; Multiphase machines; Optimization; Synchronous reluctance motor; Winding factor
Index Keywords Index Keywords
Document Type Other
Open Access Open Access
Source Science Citation Index Expanded (SCI-EXPANDED)
EID WOS:000552167900001
WoS Category Engineering, Electrical & Electronic
Research Area Engineering
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