Search results for "elettrici"
showing 10 items of 959 documents
Impact of Demand Response Control Logic on Isolated Island's Distribution Networks
2019
The work presents the results of a study regarding the impact of some Demand Response control logics on an isolated distribution network. The proposed control is divided into precise steps in which the coordination between the general aggregator controller and the single local Energy Management Systems is developed and illustrated with details. The control is applied to the flexible loads and to the storage systems of photovoltaic plants installed at the end-users' houses and connected to the network. The study is carried out delivering a suitable network model of the island's system, with the implementation of load profiles for all the loads of the network for a total simulation time of 24…
Effects of Demand Side Management on the Operation of an Isolated LV Microgrids
2019
The work presents the results of a study regarding the impact of Demand Side Management actions on flexible loads distributed at the domestic end-users' facilities in an isolated low voltage microgrid. Aim of the research study is to evaluate how the implementation of local control actions on the end-user's side can impact on the operation of the isolated microgrid. The Demand Side Management is applied by each domestic user to optimize the operation of its own resources following well-defined operative steps. The study is carried out implementing a suitable model of the microgrid in Neplan environment, while the daily controlled load profiles of the end-users are evaluated using the Montec…
A New Software Tool for Design, Optimization, and Complete Analysis of Rotating Electrical Machines Windings
2015
In this paper, a new software tool developed by the authors for ac winding design, optimization, and complete analysis is presented. In particular, this software can be used as a valid aid in design and analysis for a wide variety of motor and generator windings with generic number of phases (including the case of those machines in which some slots are left empty), pole pairs, slot number, and so on. The calculation of winding factors and the evaluation of their harmonic distribution is also accomplished. The software is implemented in the MATLAB programming environment. By means of some examples, covering the most relevant winding types, the capabilities of this software will be shown. In …
A review of health assessment techniques for distribution transformers in smart distribution grids
2020
Due to the large number of distribution transformers in the distribution grid, the status of distribution transformers plays an important role in ensuring the safe and reliable operation of the these grids. To evaluate the distribution transformer health, many assessment techniques have been studied and developed. These tools will support the transformer operators in predicting the status of the distribution transformer and responding effectively. This paper will review the literature in the area, analyze the latest techniques as well as highlight the advantages and disadvantages of current methodologies.
A general procedure for the construction of Gorges polygons for multi-phase windings of electrical machines
2018
This paper presents a simple and effective procedure for the determination of the Gorges polygon, suitable for all possible winding configurations in electrical machines. This methodology takes into account the determination of a Winding Distribution Table (WDT), in which all the information about the distribution of the currents along the stator periphery is computed and from which the Görges polygon are easily derived. The proposed method can be applied to both symmetrical and asymmetrical multi-phase windings, including concentrated, fractional, reduced and dead-coil ones. The examples provided in this paper demonstrate the versatility of the proposed method.
Direct solution of compensated radial distribution networks with constant impedance/current loads
2009
In this paper, a methodology to solve radial distribution networks, with constant current and/or impedance loads as well as shunt capacitor banks, is proposed. The techniques currently available to solve such systems are based either on iterative methods or on the bus impedance matrix. In both cases, the elaboration times are quite high since these are related, for iterative methods, to the overall number of iterations, and, for those methods based on the impedance matrix, to the inversion of the admittance matrix. The method developed here is the extension of a technique that is valid to solve networks made of impedances with one supply point. The methodology can also be applied in the sol…
Minimum power losses by using droop coefficients regulation method with voltage and frequency constraints in islanded microgrids
2018
In this paper, a droop coefficients regulation methodology is proposed for an islanded microgrid to optimize the power losses. Based on the P-f and Q-V relations to adjust the droop coefficients at every loading condition, the optimized operating set point generates minimum power losses operation while satisfying the constraints of voltage and frequency limitation. A 9-bus case study is here implemented to show the effectiveness of this new approach as well as the improved operation quality of the system.
Optimal power flow for technically feasible energy management systems in islanded microgrids
2016
This paper presents a combined optimal energy and power flow management for islanded microgrids. The highest control level in this case will provide a feasible and optimized operating point around the economic optimum. In order to account for both unbalanced and balanced loads, the optimal power flow is carried out using a Glow-worm Swarm Optimizer. The control level is organized into two different sub-levels, the highest of which accounts for minimum cost operation and the lowest one solving the optimal power flow and devising the set points of inverter interfaced generation units and rotating machines with a minimum power loss. A test has been carried out for 6 bus islanded microgrids to …
Experimental Characterization of a Double Receiver Dynamic Wireless Charging System
2020
The aim of this work is the characterization of a dynamic wireless charging system low power prototype and the validation of a simplified mathematical model of the employed double D coils. The difference between a single receiver and a dual receiver system is also shown, highlighting how the last one can significantly reduce the costs of the charging infrastructure.
Design and performances of a high temperature superconducting axial flux generator
2013
An important quality index of electric machine is the power density: it is known that axial flux machine tends to have a higher power density than the radial machines. As a result they are becoming more and more used in applications where the power density is a critical issues. However, the best way to enhance the power density is to increase the value of the airgap field and this could be achieved by using a superconducting excitation. Many projects have been developed in the world in order to develop both superconducting generator and superconducting motor, but in most of these programs the geometry of the machine has been based on radial machines [1]. All of these approaches show the fea…