Efficiency Enhancement of Permanent Magnet Synchronous Motor Drives by on-Line Loss Minimization Approaches

In this paper, a new loss minimization control algorithm for inverter-fed permanent-magnet synchronous motors (PMSMs), which allows for the reduction of the power losses of the electric drive without penalty on its dynamic performance, is analyzed, experimentally realized, and validated. In particular, after a brief recounting of two loss minimization control strategies, namely, the "search control" and the "loss-model control," both a new modified dynamic model of the PMSM (which takes into account the iron losses) and an innovative "loss-model" control strategy are presented. Experimental tests on a specific PMSM drive employing the proposed loss minimization algorithm have been performed, aiming to validate the actual implementation. The main results of these tests confirm that the dynamic performance of the drive is maintained, and in small motors enhancement up to 3.5% of the efficiency can be reached in comparison with the PMSM drive equipped with a more traditional control strategy

An Experimental Comparison between an Ironless and a Traditional Permanent Magnet Linear Generator for Wave Energy Conversion

Permanent Magnet Linear Generators (PMLGs) are currently being studied for sea wave energy harvesting. Typically, a PMLG consists of an iron-made armature and a moving translator. The permanent magnets adoption produces parasitic effects, such as cogging force, and the machine weight increment. A solution could be the adoption of an ironless configuration, accepting a power density reduction. This paper investigates the use of ironless PMLGs in sea wave energy conversion systems by an experimental comparative analysis between an iron PMLG prototype and an ironless PMLG prototype, which share the same geometry. The main electrical and mechanical parameters (resistance, mass, and magnetic fields) were preliminarily measured. Subsequently, open-circuit and load tests were carried out to compare the induced voltages, the energy transferred to a resistive load, efficiency and the load average power. The reported comparison shows that iron PMLG performances are significantly superior to the ironless ones during the open-circuit tests, as expected. However, the analysis carried out through the load tests shows that the cogging force significantly limits the energy production, obtaining similar values in both machines. Therefore, the experimental tests justify the use of ironless machines in sea wave energy harvesting, where the maximization of energy production is a relevant target

The first transcriptome of Italian wall lizard, a new tool to infer about the Island Syndrome

Some insular lizards show a high degree of differentiation from their conspecific mainland populations, like Licosa island lizards, which are described as affected by Reversed Island Syndrome (RIS). In previous works, we demonstrated that some traits of RIS, as melanization, depend on a differential expression of gene encoding melanocortin receptors. To better understand the basis of syndrome, and providing raw data for future investigations, we generate the first de novo transcriptome of the Italian wall lizard. Comparing mainland and island transcriptomes, we link differences in life-traits to differential gene expression. Our results, taking together testis and brain sequences, generated 275,310 and 269,885 transcripts, 18,434 and 21,606 proteins in Gene Ontology annotation, for mainland and island respectively. Variant calling analysis identified about the same number of SNPs in island and mainland population. Instead, through a differential gene expression analysis we found some putative genes involved in syndrome more expressed in insular samples like Major Histocompatibility Complex class I, Immunoglobulins, Melanocortin 4 receptor, Neuropeptide Y and Proliferating Cell Nuclear Antigen

Does Presentation Format Influence Visual Size Discrimination in Tufted Capuchin Monkeys (Sapajus spp.)?

Most experimental paradigms to study visual cognition in humans and non-human species are based on discrimination tasks involving the choice between two or more visual stimuli. To this end, different types of stimuli and procedures for stimuli presentation are used, which highlights the necessity to compare data obtained with different methods. The present study assessed whether, and to what extent, capuchin monkeys\u27 ability to solve a size discrimination problem is influenced by the type of procedure used to present the problem. Capuchins\u27 ability to generalise knowledge across different tasks was also evaluated. We trained eight adult tufted capuchin monkeys to select the larger of two stimuli of the same shape and different sizes by using pairs of food items (Experiment 1), computer images (Experiment 1) and objects (Experiment 2). Our results indicated that monkeys achieved the learning criterion faster with food stimuli compared to both images and objects. They also required consistently fewer trials with objects than with images. Moreover, female capuchins had higher levels of acquisition accuracy with food stimuli than with images. Finally, capuchins did not immediately transfer the solution of the problem acquired in one task condition to the other conditions. Overall, these findings suggest that - even in relatively simple visual discrimination problems where a single perceptual dimension (i.e., size) has to be judged - learning speed strongly depends on the mode of presentation

Maximum Torque per Ampere Control strategy for low-saliency ratio IPMSMs

This paper deals with electrical drives employing low-saliency ratio interior permanent magnet synchronous motors. In particular, in order to help the designers choosing the best control algorithm, the performances of the Maximum Torque Per Ampere Control (MTPA) and the Field Orientation Control (FOC) are here both theoretically and experimentally assessed and compared, by using, as performance indicators, the torque-current ratio and the power losses. The tests are carried out on a low-power motor for various speeds and loads by implementing the two control strategies in a dSPACE® rapid prototyping system. The results show that the Maximum Torque Per Ampere algorithm has some appreciable advantages mainly for high load conditions of operation

METODOLOGIE A CONFRONTO IN UN COMPITO DI DISCRIMINAZIONE VISIVA. UNO STUDIO NEL CEBO DAI CORNETTI (SAPAJUS SPP.)

The aim of the study was to assess the ability of tufted capuchin monkeys (Sapajus spp.) to solve a visual discrimination problem presented with different procedures (computerised and non-computerised). The study was done in collaboration with the Max Planck Institute for Evolutionary Anthropology of Leipzig and it had yielded results of methodological relevance in comparative visual cognition research. In particular, it has shown that the presentation of the same discrimination task by using different methodologies, even if equivalent from a functional point of view, leads to significant differences in learning speed

Analysis a DSP Implementation and Experimental Validation of a Loss Minimization Algorithm Applied to Permanent Magnet Synchronous Motor Drives

In this paper a new loss minimization control algorithm for inverter-fed permanent-magnet synchronous motors (PMSM), which allows to reduce the power losses of the electric drive without penalty on its dynamic performances, is analyzed, experimentally realized and validated. In particular, after a brief recall of two loss minimization control strategies (the "search control" and the "loss-model control"), both a modified dynamic model of the PMSM, which takes into account the iron losses, and a "loss-model" control strategy, are treated. Experimental tests on a specific PMSM drive employing the proposed loss minimization algorithm were performed aiming to validate the actual implementation. The main results of these tests confirm that the dynamic performances of the drive are maintained, and enhancement up to 3.5% of the efficiency can be reached in comparison to the PMSM drive equipped with a more traditional control strategy

La psicoanalisi familiare e di coppia

La Giornata è organizzata dal Dipartimento di Teorie e Metodi delle Scienze Umane e Sociali (TEOMESUS), dalla Scuola di Dottorato in Scienze Psicologiche, Pedagogiche e Linguistiche e realizzata col patrocinio del Dipartimento di Psicoanalisi Applicata alla Coppia e alla Famiglia e dell’Association Internationale de Psychanalyse de Couple et de Famille (AIPCF). L'evento si propone quale momento riflessione teorico-clinica su alcuni nodi cruciali del lavoro psicoanalitico con coppie e famiglie

Effect of stimulus type and experimental procedure on a visual discrimination task. A study on tufted capuchin monkeys (Sapajus spp.).

The study was aimed at assessing if capuchin monkeys’ learning ability to discriminate stimuli by size varied on the basis of both stimulus types (images, foods and objects) and kind of procedures used for stimulus presentation (computerised and non-computerised). Moreover, subjects’ ability to generalise the solution of the problem across different task conditions has been evaluated