Search results for " INDUCTION"
showing 10 items of 526 documents
A Flux and Speed Observer for Sensorless SPIM Applications
2010
It is usual to find single-phase induction motor (SPIM) in several house, office, shopping, farm, and industry appliances, which is become more sophisticated and requires the development of high performance alternatives to drive a SPIM. All proposed strategies to improve the performance SPIM need the evaluation of the rotational speed or position information. Since the use of conventional sensors to measure the rotational speed cannot be justified for SPIM applications, the adoption of a sensorless strategy is a more reasonable option for these cases. This paper presents a flux and speed observer for sensorless applications involving SPIMs. The performance of the proposed observer is verifi…
Investigation of motor current signature and vibration analysis for diagnosing rotor broken bars in double cage induction motors
2012
This paper investigates the detectability of rotor broken bars in double cage induction motors using current signature and vibration analysis techniques. Double cage induction motors are commonly used for applications where successive loaded starts-up are mandatory. Experimental results were performed under healthy and faulty cases, and for different load conditions using each technique. Rotor broken bars fault detection based on sideband current components may fails due to the presence of inter bar currents that reduce the degree of rotor asymmetry, yielding to a decrease of the magnitude of these spectral components. But inter bar currents produce core vibrations in the axial direction, w…
Performance comparison of tubular linear induction motors with different primary winding connections
2014
This paper presents an experimental characterization and comparison of the performances achieved by a tubular linear induction motor (TLIM) prototype with different typologies of primary winding connections. In particular, three configurations are described: full-pitch star, 5/6 shortened pitch star and 5/6 shortened pitch double star. For this purpose, an experimental test bench at the SDESLAB laboratory (University of Palermo) has been set-up and the results obtained from the tests have allowed to identify which type of winding configuration can be chosen in dependence of the type of application intended for the motor. In addition, this experimental study is suitable for TLIM winding desi…
Method for designing PI-type fuzzy controllers for induction motor drives
2001
The paper illustrates a new systematic method for designing PI-type fuzzy controllers for direct field-oriented controlled induction motor drives. First, linear and decoupled models expressing the dynamics of speed, rotor flux, direct and inquadrature stator currents are derived using a nonlinear static compensator and choosing convenient input variables. Then, to guide the dynamics of the above quantities, four conventional PI controllers are designed independently, choosing their bandwidths conveniently. Finally, the input and output scale factors of PI-type fuzzy controllers are derived from the conventional PI controller parameters. The whole drive controller also includes a rotor flux …
Vibration signature analysis for rotor broken bar diagnosis in double cage induction motor drives
2013
The paper investigates the diagnosis of rotor broken bars in field oriented controlled (FOC) double cage induction motor drives, using current and vibration signature analysis techniques. The Impact of the closed loop control system cannot be neglected when the detection of asymmetries in the machine are based on the signature analysis of electrical variables. The proposed diagnosis approach is based on optimized use of wavelet analysis by a pre-processing of phase current or axial/radial vibration signals. Thus, the time evolution of the tracked rotor fault components can be effectively analyzed. This paper shows also the relevance of the fault components computed from axial vibration sign…
Diagnosis of mechanical unbalance for double cage induction motor load in time-varying conditions based on motor vibration signature analysis
2013
This paper investigates the detectability of mechanical unbalance in double cage induction motor load using motor vibration signature analysis technique. Rotor imbalances induce specific harmonic components in electrical, electromagnetical, and mechanical quantities. Harmonic components characteristic of this category of rotor faults, issued from vibration signals analysis, are closely related to rotating speed of the rotor, which complicates its detection under non-stationary operating conditions of the motor. Firstly, experimental results were performed first under healthy and mechanical load unbalance cases, for different load levels under steady-state operating conditions to evaluate th…
Closed-loop bandwidth impact on MVSA for rotor broken bar diagnosis in IRFOC double squirrel cage induction motor drives
2013
This paper investigates the detectability of rotor broken bars in indirect rotor flux oriented control (IRFOC) for variable speed double cage induction motor drives, using vibration signature analysis techniques. The Impact of the closed loop control system cannot be neglected when the detection of rotor asymmetries in the machine is based on the signature analysis of electrical or mechanical variables. Therefore, the investigation of rotor fault components for different bandwidths of closed-loop regulators is necessary to evaluate its relevance in the above listed variables. This paper investigates the impact of the control system on relevance of the fault components computed from axial an…
Ligninolytic potential of Curvularia kusanoi L7 laccases for animal production
2020
The present research was conducted with the objective of evaluating the ligninolytic potential of Curvularia kusanoi L7 laccases in improving the nutritional quality of fibrous substrates for animal feed. Laccase production was obtained from C. kusanoi L7 under native conditions by solid submerged fermentation of wheat bran and by biological interactions with Trichoderma viride M5-2 and Trichoderma pleuroticola. The enzymes were purified from the culture broths by triphasic partition. The degradative potential of native and induced laccases where evaluated by determining foliar lignololytic capacity, raw wheat (Triticum aestivum) straw delignification and the effect of enzyme pretreatment o…
Replication of HSV-1 in murine peritoneal macrophages: comparison of various virus strains with different properties.
1984
The in vitro replication of eleven different strains of herpes simplex virus type 1 was studied in resident or thioglycollate-stimulated mouse macrophages. The strains of herpes simplex virus differed in the type of cytopathic effect, induction capacity for herpes simplex virus coded thymidine kinase and pathogenicity in the mouse. Herpes simplex virus replicated better in thioglycollate-stimulated macrophages than in resident macrophages. In vitro ageing of macrophages increased their replicative potency. Herpes simplex virus replicated better in macrophages from homozygous bg/bg C57/BL6J mice than in macrophages from their heterozygous littermates. Separation of macrophages on discontinuo…
Experimental characterization and comparison of TLIM performances with different primary winding connections
2017
Abstract This paper presents an experimental characterization and comparison of the performances achieved by a Tubular Linear Induction Motor (TLIM) prototype with different typologies of primary winding connections. More in detail, three different configurations have been considered, analyzed and discussed: full-pitch star, 5/6 shortened pitch star and 5/6 shortened pitch double star. For this purpose, an experimental test bench at the Sustainable Development and Energy Saving Laboratory (SDESLab), University of Palermo, Italy, has been set-up. The obtained results have allowed the identification of the best winding configuration for different applications intended for the motor. Moreover,…