Search results for " multilevel"
showing 10 items of 65 documents
Enhanced Modelling for Extended Performance Analysis of Interior Permanent Magnet Synchronous Machine Drive fed with Cascaded H-Bridges Multilevel In…
2021
This paper presents a comparative simulation analysis of an Interior Permanent Magnet Synchronous Machine (IPMSM) performance once fed by a traditional three-phase two-level inverter and then using a three-phase five-level Cascaded H-Bridges Multilevel Inverter (CHBMI). For this purpose, an enhanced mathematical model of the IPMSM, that take into account simultaneously saturation, cross-coupling, spatial harmonics and iron loss effects, has been employed. Furthermore, two different PWM modulation strategies have been considered. The study was conducted for several working conditions, evaluating the impact of CHBMI adoption on the IPMSM performance in terms of improved efficiency and torque …
Compromiso afectivo, liderazgo participativo e innovación del empleado: una investigación multinivel
2019
Research investigating the relationship between organizational affective commitment and employee innovation has yielded scarce and inconsistent findings. This study examined the role of participative leadership in a team as a boundary condition of the effectiveness of organizational affective commitment predicting employee innovation. Data were collected from 343 employees in 34 teams from different Italian companies. The results from hierarchical linear modelling analysis indicated that the relationship between organizational affective commitment and employee innovation was stronger when team-level participative leadership was high. Our findings provide meaningful insights regarding the co…
A Novel Symmetrical Boost Modulation Method for qZS-based CHB Inverters
2020
Quasi-Z-source cascaded H-bridge (qZS-CHB) inverters are arising as an innovation in the field of the electrical conversion for PV applications. This type of converters inherit the advantages of multilevel inverters and single-stage configuration. In this context, this paper proposes a novel symmetrical boost modulation strategy for qZS CHB multilevel inverters to increase the performance in terms of voltage stresses and power quality. The novelty lies in the adoption of a different concept to generate the shoot-through states compared to the traditional methods. Simulation analysis in a grid connected application to evaluate the benefits of this boost method is performed in the MATLAB/PLEC…
The Cross-Level Moderation Effect of Resource-Providing Leadership on the Demands—Work Ability Relationship
2021
Employees in female-dominated sectors are exposed to high workloads, emotional job demands, and role ambiguity, and often have insufficient resources to deal with these demands. This imbalance causes strain, threatening employees’ work ability. The aim of this study was to examine whether resource-providing leadership at the workplace level buffers against the negative repercussions of these job demands on work ability. Employees (N = 2383) from 290 work groups across three countries (Germany, Finland, and Sweden) in female-dominated sectors were asked to complete questionnaires in this study. Employees rated their immediate supervisor’s resource-providing leadership and also self-reported …
Consumption Patterns and Family Life-Cycle. Some Evidence from Italy
2015
As a social and economic entity the family is changing continuously. Changes in family size and composition have significant effects on the family decision making process. The Italian context is an interesting subject for research as a result of the impact of demographic and economic changes in the early 2000s on new family structures and economic behaviour. Furthermore, in Italy in contrast to the past, both men and women are aiming for job security and satisfaction before marrying and starting a family. In the light of that, it is particularly interesting to investigate if consumption behaviour changes along the life cycle stages. Considering different family life stages enables us to exp…
Experimental study on B-spline-based modulation schemes applied in multilevel inverters for electric drive applications
2019
This work presents the design, simulation, and experimental validation of new B-Spline-based modulation techniques applied to a Multilevel Power Inverter (MPI), particularly focusing the attention on the harmonic content of the output voltages of the inverter. Simulation and experimental results are proposed and discussed, mainly describing the potential benefits, such as the increase of the multi-level operation of the converter, and drawbacks (low-order harmonics) related to the adoption of B-Spline functions for multilevel inverters applied in the field of electrical drives.
Testing for convergence from the micro-level
2011
Empirical convergence analysis is typically envisaged from a macro aggregate perspective. However, researchers have recently highlighted how investigating convergence at the disaggregate level may yield interesting insights into the convergence debate. In this paper, we suggest an approach that allows exploiting large micro panels to test for convergence. Compared to the traditional convergence analysis, this approach allows obtaining beta- and sigma-like convergence parameters for both the micro and the macro level of interest. We provide a practical example that analyses productivity convergence across firms and provinces using a large sample of Italian firms.
Coopetition Strategy and Entrepreneurial Opportunities: Advantages from Multilevel Analyses
2018
The study aims to provide a set of insights concerning the benefits associated with applying a multilevel perspective to the investigation of the link between coopetition strategies and entrepreneurial opportunities. We emphasize that a firm capability to recognize, form, and exploit business opportunities is strictly connected to its coopetitive strategy. In order to fully understand the potential of coopetitive strategies, the focus has to be not just on the examination of the single coopetitive relationship, but also on the micro-foundations underlying such strategies: i.e. the role covered by entrepreneurs’ or CEOs’ personal traits, heuristics, and previous experiences. We also suggest …
Resisting the extortion racket: an empirical analysis
2018
While the contributions on the organized crime and Mafia environments are many, there is a lack of empirical evidence on the firm’s decision to resist to extortion. Our case study is based on Addiopizzo, an NGO that, from 2004, invites firms to refuse requests from the local Mafia and to join a public list of “non-payers”. The research is based on a dataset obtained linking the current administrative archives maintained by the chambers of commerce and the list updated by the NGO. The objective of this paper is twofold: first, to gather sound data on the characteristics of the Addiopizzo joiners; second to model the probability to join Addiopizzo by a two-level logistic regression model. We …
Experimental analysis with FPGA controller-based of MC PWM techniques for three-phase five level cascaded H-bridge for PV applications
2016
The FPGA represents a valid solution for the design of control systems for inverters adopted in the field of PV systems because of their high flexibility of use. This paper presents an experimental analysis of the MC SPWM techniques for a three-phase, five-level, cascaded H-Bridge inverter with FPGA controller-based. Several control algorithms are implemented by means of the VHDL programming language and the output voltage waveforms obtained from the main PWM techniques are compared in terms of THD%. Simulation and experimental results are analysed, compared and discussed.