807 research outputs found
International Standards for the Induction Motor Efficiency Evaluation: a Critical Analysis of the Stray-Load Losses Determination
No full textMotor efficiency has to be measured or calculated in accordance with international standards. The most important standards are the IEEE 112-B, IEC 34-2, and JEC 3 . In this paper, a comparison of the measurement procedures defined by these international standards is reported, together with some comments on the prescribed methodologies. The comparison is based on experimental results obtained by tests on four general-purpose three-phase induction motors. The stray-load loss measurement represents a critical key for the correct evaluation of the motor efficiency. For this reason, a critical analysis of this type of losses has been performed. In particular, in order to understand which are the most critical quantities that influence their evaluation, the stray-load loss sensitivity to the measurement errors is analyzed. In the final part of the paper the temperature influence, on the conventional iron losses, is experimentally analyzed. The performed tests show that the temperature difference between the no-load test and the motor real operative conditions is not negligible
Thermal analysis of induction and synchronous reluctance motors
No full textIn this paper, the thermal behavior of two induction motors (2.2 and 4 kW, four poles) and two synchronous reluctance motors [(SynRMs) transverse-laminated] are investigated and compared. Both motor types use the same stator but have different rotors. Using a lumped-parameter simulation program, a thermal analysis has been also carried out, and the obtained results have been compared with the experimental ones. A direct comparison of the thermal behavior of the two motor types has thus been made for constant load and constant average copper temperature conditions. Inasmuch as the SynRM has negligible rotor losses compared with the induction motor, it is capable of a larger rated torque, from 10% to more than 20%, depending on the relative size of end connections and motor lengt
Position-sensorless control of permanent-magnet-assisted synchronous reluctance motor
No full textThe sensorless control of permanent-magnet-assisted synchronous reluctance (PMASR) motors is investigated, in order to conjugate the advantages of the sensorless control with full exploitation of the allowed operating area, for a given inverter. An additional pulsating flux is injected in the d-axis direction at low and zero speed, while it is dropped out, at large speed, to save voltage and additional loss. A flux-observer-based control scheme is used, which includes an accurate knowledge of the motor magnetic behavior. This leads, in general, to good robustness against load variations, by counteracting the magnetic cross saturation effect. Moreover, it allows an easy and effective correspondence between the wanted torque and flux and the set values of the chosen control variables, that is d-axis flux and q-axis current. Experimental verification of the proposed method is given, both steady-state and dynamic performance are outlined. A prototype PMASR motor will be used to this aim, as part of a purposely assembled prototype drive, for light traction application (electric scooter
Cross-Saturation Effects in IPM Motors and Related Impact on Sensorless Control
No full textPermanent-magnet-assisted synchronous reluctance motors are well suited to zero-speed sensorless control because of their inherently salient behavior. However, the cross-saturation effect can lead to large errors on the position estimate, which is based on the differential anisotropy. These errors are quantified in this paper as a function of the working point. The errors that are calculated are then found to be in good accordance with the purposely obtained experimental measurement
Impact of cross-saturation in sensorless control of transverse-laminated synchronous reluctance motors
No full textSynchronous reluctance (SyR) motors are well suited to a zero-speed sensorless control, because of their inherently salient behavior. However, the cross-saturation effect can lead to large errors on the position estimate, which is based on the differential anisotropy. These errors are quantified in the paper, as a function of the working point. The so-calculated errors are then found in good accordance with the purposely obtained experimental measurements. The impact of the amplitude of the carrier voltage is then pointed out, leading to a mixed (carrier injection plus electromotive force estimation) control scheme. Last, a scheme of this type is used, with a commercial transverse-laminated SyR motor. The robustness against cross-saturation is shown, in practice, and the obtained drive performance is pointed out proving to be effective for a general-purpose applicatio
Dry matter loss and lipid oxidation evaluation of soybeans during storage at elevated moisture content and temperature
No full textSubmission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2023-08-01The student, Mariane Pastorelli Latanze, accepted the attached license on 2021-07-02 at 06:43.The student, Mariane Pastorelli Latanze, submitted this Thesis for approval on 2021-07-02 at 07:15.This Thesis was approved for publication on 2021-07-08 at 16:37.DSpace SAF Submission Ingestion Package generated from Vireo submission #16745 on 2022-01-12 at 13:03:52Made available in DSpace on 2022-01-12T22:54:08Z (GMT). No. of bitstreams: 2
PASTORELLILATANZE-THESIS-2021.pdf: 1675350 bytes, checksum: 9ed6355d7325075cbcf2bc1cfcded84f (MD5)
LICENSE.txt: 4223 bytes, checksum: eacfd093d1281ed58e5381ebad1fb934 (MD5)
Previous issue date: 2021-07-08Embargo set by: Seth Robbins for item 121195
Lift date: 2024-01-12T22:54:14Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 121195
Lift date: 2024-01-12T22:55:09Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 121195
Lift date: 2024-01-12T22:56:20Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemAuthor requested closed access (OA after 2yrs) in Vireo ETD systemLimite
Cross-saturation in synchronous reluctance motors of the transverse-laminated type
No full textThe cross-saturation phenomenon in synchronous reluctance motors is extensively analyzed, with a main reference to motors of the transverse-laminated type. A mixed, theoretical and experimental approach is adopted, aiming at definition of motor's behavior when large overload currents are driven, up to ten times the rated current. As a consequence, a special test and measuring procedure has been adopted. The obtained results are used to check the validity of the adopted model and to prove the unexpected overload performance of this motor. Finally, the tendential behavior at infinite current is discussed
- …
