0000000000130152
AUTHOR
Claudio Nevoloso
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 fie…
Enhanced mathematical modelling of interior permanent magnet synchronous machines for loss minimization control
Energy management is a fundamental facility for humanity. At present, the awareness that renewable energy cannot satisfy the entire energy needs of the community and that traditional energy sources have a limited duration makes it imperative to address the problem of their careful and responsible use. Therefore, the need for an intelligent and functional use of energy has led the technical-scientific community to concentrate its efforts on the issues of sustainable development and energy savings. The electric drives industrial sector has suffered this influence in a visceral way. This sector plays a leading role in the industrial frame as it is one of the main consumers of electricity. More…
Switching Frequency Effects on the Efficiency and Harmonic Distortion in a Three-Phase Five-Level CHBMI Prototype with Multicarrier PWM Schemes: Experimental Analysis
The current climatic scenario requires the use of innovative solutions to increase the production of electricity from renewable energy sources. Multilevel Power Inverters are a promising solution to improve the penetration of renewable energy sources into the electrical grid. Moreover, the performance of MPIs is a function of the modulation strategy employed and of its features (modulation index and switching frequency). This paper presents an extended and experimental analysis of three-phase five-level Cascaded H-Bridges Multilevel Inverter performance in terms of efficiency and harmonic content considering several MC PWM modulation strategies. In detail, the CHBMI performance is analyzed …
Field Oriented Control of IPMSM Fed by Multilevel Cascaded H-Bridges Inverter with NI-SOM sbRIO-9651 FPGA controller
Electrical drives fed by Multilevel Inverters (MIs) are of considerable interest for traction and e-mobility applications. In detail, Cascaded H-Bridge Multilevel Inverter (CHBMI) is a promising solution for electrical drive optimization purposes in terms of efficiency, safety, integration and flexible use of energy sources. The aim of this paper is the experimental implementation of the field-oriented control strategy of Interior Permanent Magnet Synchronous Machine (IPMSM) fed by CHBMI by use of NI-SOM sbrRIO-9651 FPGA controller. This FPGA controller can be programmable in the LabVIEW programming environment with the consequent benefits of graphical programming. The paper address the acq…
Reduction of cogging force in linear generators for wave energy harvesting
Due to huge energy potential of sea waves, many technologies have been proposed in the last few years. Some concepts have been developed and sometimes also tested in the open sea. Some prototypes use linear generators to directly convert the vertical motion of buoys into electrical energy. This solution minimizes the numbers of energy conversion steps, increasing the energy efficiency. At the same time, the limited numbers of components could also increase the reliability of the wave energy converter. For this reason, the development of linear generators is considered with great interest. This paper investigated the cogging force, a magnetic force due to the interaction between the magnets …
Dead-time impact on the harmonic distortion and conversion efficiency in a three-phase five-level Cascaded H-Bridge inverter: mathematical formulation and experimental analysis
To avoid leg short-circuit in inverters, dead time must be introduced on leg gate signals. Dead time affects the inverter output voltage fundamental harmonic amplitude, voltage harmonic distortion and inverter efficiency by introducing additional voltage drops. In this regard, dead time effects have been widely investigated for traditional two-level three-phase voltage source inverters in the literature but not extensively for multilevel topology structures. This paper provides a detailed analysis of dead time impact on the harmonic distortion and efficiency of Cascaded H-Bridges Multilevel Inverters (CHBMIs). For this purpose, a general mathematical formulation to determine voltage drop du…
Stability of Microgrids: An Application of Virtual Synchronous Generator
The objective of this paper is to illustrate an alternative control algorithm for power converters which have the task of introducing the energy generated by systems based on the use of renewable sources such as, photovoltaic or wind power, in to small-sized networks, microgrids. Virtual Synchronous Generator can operate both in parallel to the main network as well as in isolated and autonomous conditions (islanding-mode). The contribute of this work is to drive a consolidate approach, made in time domain, in a more flexible and less time-consuming approach based on Park transformation.
Recursive Selective Harmonic Elimination for Multilevel Inverters: Mathematical Formulation and Experimental Validation
A recursive method that eliminates +1 harmonics and their respective multiples from the output voltage of a cascaded H-bridge multilevel inverters with = 2 dc sources ( = 1, 2, 3,...) is proposed. It solves 2×2 linear systems with not singular matrices and always gives an exact solution with very low computational effort. Simulated results in three-phase five, nine, seventeen and thirty three level CHB inverters, and experimental results in five-level inverter demonstrate the validity of the method.
Modelling, Simulation and Characterization of a Supercapacitor in Automotive Applications
In the energy storage field, supercapacitors (SCs) are gaining more and more attention thanks to features such as high-power density, high life cycles and lack of maintenance. In this article, an improved SC three-branches model which considers the residual charge phenomenon is presented. The procedure to estimate the model parameters and the related experimental set-up are presented. The parameter estimation procedure is repeated for several SCs of the same type. The average parameters are then obtained and used as initial guesses for a recursive least square optimization algorithm, to increase the accuracy of the model. The model of a single SC is then extended to SC banks, testing differ…
State of art and economic evaluation of wave energy converters. A case study
The even increasing energy demand in the world is a relevant problem for the modern society. The energy supply from fossil fuels has become a critical aspect due to the progressive reduction of reserves and political instability among the Countries. For these reasons, the exploitation of renewable energy sources is looked with a great interest. In this context, solar, wind, geothermal, hydropower, and biomass can be successfully used through commercial technologies. Other potential renewable energy sources could have potential applications in the next future. Among these, sea wave is considered a very promising energy source, especially for small islands. In this context, the paper propones…