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To meet different loading requirements in the metal industry, special attention must be paid to the operational performances and start-up characteristics of those electric motors implemented for desired driven applications. However, because of the global warming and energy conservation concerns, the enforced operational regulations have increased the complexity of those commonly applied induction motors for supplying the desired equipment driven forces. By adopting the same stator, the synchronous reluctance motor (SynRM) can be achieved with properly redesigned rotor structure of an induction motor. Due to its robust structure and lack of secondary copper loss, it is very competitive for the related hoist, punch, roller, and pump applications. Furthermore, by inserting adequate ferrite permanent magnets and conductors into the rotor barriers, composition designs of the direct-on-line SynRMs (DOL_SynRMs) will also be proposed. The operational characteristics of the DOL_SynRMs for fulfilling different specifications will all be thoroughly investigated and confirmed by experimental measurements. The DOL_SynRM structures that can provide potential alternatives for related high-efficiency metal industry-driven applications can thus be validated. [ABSTRACT FROM AUTHOR]

To meet the higher operational efficiency regulations of electric motors due to energy-conservation concerns, specific design efforts have been dedicated to those motors for different industrial application requirements. Since the synchronous reluctance motor (SynRM) is generally designed based on the same stator structure as that of the induction motor and operated at synchronous speed, whereas no electrical contact to its rotor, it is capable of providing a robust structure and no rotor copper loss. Such features are very attractive for the related hoist, punch, roller, and pump applications that are commonly adopted in the metals industry. By equipping adequate power factor correction and line-start capabilities, the detailed designs and performance analyses of the SynRMs with a common rotor structure composed by laminated electrical steels will be proposed. Based on this common rotor structure, the operational characteristics of the SynRMs for fulfilling different specifications will all be thoroughly investigated. Confirmed by experimental validations, valuable guidance for related SynRM constructions and applications can thus be provided for metals industry and motor designers. [ABSTRACT FROM AUTHOR]

By appropriately inserting ferrite magnets into the rotor of a synchronous reluctance motor (SynRM), the machine operational power factors and torque outputs can be improved. With specific rotor structures to accommodate those ferrites, many of these permanent-magnet-assisted SynRMs (PMA-SynRMs) have been proposed to comply the expected operational objectives. For construction convenience, the ferrites that being inserted into the flux barriers of these PMA-SynRMs are generally in rectangular shapes; hence, some adjustments on the rotor flux barriers and additional bridges are required. Such changes will inevitably affect the performance of the original SynRMs with optimized rotor structures, and these tradeoffs are thus to be recovered by parts of those adopted ferrites. This paper will provide an evaluation index that can characterize the performance of PMA-SynRMs with different volume compositions of the ferrites, along with the impact assessments of the SynRMs with modified flux barriers such that those ferrites can be properly allocated. Based on the designs obtained from thorough 3-D finite-element analyses, a 3-hp PMA-SynRM will be constructed and the related experimental measurements will also be supported to validate the design adequacies. [ABSTRACT FROM AUTHOR]

With the ever rigorous operational efficiency requirements, effective copper loss reduction is one of the viable approaches for small-power alternative current motors. Among those cost-effective schemes, by eliminating the rotor windings while keeping the same stator structures, the synchronous-reluctance motor (SynRM) offers a potential substitute for those small-power applications that the induction motors are commonly adopted. Since the key factor that affects the SynRM-generated torque will be the difference between its direct-axis and quadrature-axis inductances, by arranging the rotor field paths aligned to the direct axis and by considering the possible cross-coupling magnetic saturations on the rotor ribs and segments, the performance impacts due to field path arrangements on the rotor will be thoroughly evaluated by 3-D finite-element analyses. From the experimental measurements, it is clear that the operational objectives can be achieved, and the adequacy of the proposed design guidance can then be confirmed. [ABSTRACT FROM AUTHOR]