Search results for "elettrici"
showing 10 items of 959 documents
Experimental investigation on high efficiency real-time control algorithms for IPMSMs
2014
This paper describes an experimental investigation on the power losses variations occurring in an Interior Permanent Magnet Synchronous Motor (IPMSM) with respect to the direct axis current component. Such investigation can be useful to determine a mathematical model accounting for copper, iron and mechanical friction losses, and for the arrangement of a speed control drive system equipped with a real-time power losses minimization algorithm. In particular, a test bench has been set up in order to carry out all measurements and the final power loss identification. The test bed is composed by a IPMSM drive with a field oriented control (FOC) strategy, a power analyzer, a dynamometric brake a…
Overcoming synchronization issues in wireless technology Partial Discharge measurement
2016
In this paper, several aspects of the fundamentals of wireless Partial Discharge (PD) measurements are first discussed. Then, the relevance of the problem of voltage synchronization in PD wireless diagnosis is outlined. When portable instruments are used for PD detection, the main issue is the voltage measurement at the site where the PD detection is carried out. When such analysis is carried out over shielded cables, the AC (50/60 Hz) voltage reference signal is not easily detectable, while one of the basic parameters for PD diagnosis, the displacement of the inception voltage of the PD as compared to the reference voltage, is not available. Even if highperformance sensors are readily avai…
Integration of distributed on site control actions via combined photovoltaic and solar panels system
2009
A systematic evaluation of the potential energy saving and CO2 emissions reduction on buildings was carried out, when a renewable energy system is locally installed. The exploitation of a combined solar and photovoltaic system and the integration of suitable energy management actions were deeply investigated. A model of these solar and photovoltaic components has been developed and included within a complete house simulator, capable to precisely figure out the daily electric energy consumptions of typical apartments and to measure the positive actions induced by the added renewable energy. Saving up to 40% on the energy consumptions and even more savings on wiring losses seems to be easily …
Lightning-current distribution in MV grids interconnected earthing systems
2017
The paper presents first investigations results on the effects of lightning stroke on medium voltage (MV) installations' earthing systems, connected together with the metal shields of the MV distribution grid cables. The study enables to evaluate the distribution of the lightning current among interconnected earth electrodes in order to assess if the interconnection, usually done for reducing earth potential rise during an earth fault, can give place to dangerous situations far from the installation hit by the lightning stroke. Two case studies of direct lightning stroke are presented and discussed: two interconnected MV substations of the MV grid; a high voltage/medium voltage (HV/MV) stat…
An experimental study on relationship between LED lamp characteristics and non image-forming
2017
The general aim of the experimental study, presented in this paper, was that to investigate the relationship between the characteristics of five different types of LED (Light Emitting Diode) lamps, which are nowadays those allowing the highest energy consumption reduction, and the humans non image-forming (NIF) reactions.
Active load sharing technique for on-line efficiency optimization in DC microgrids
2017
Recently, DC power distribution is gaining more and more importance over its AC counterpart achieving increased efficiency, greater flexibility, reduced volumes and capital cost. In this paper, a 24-120-325V two-level DC distribution system for home appliances, each including three parallel DC-DC converters, is modeled. An active load sharing technique is proposed for the on-line optimization of the global efficiency of the DC distribution network. The algorithm aims at the instantaneous efficiency optimization of the whole DC network, based on the on-line load current sampling. A Look Up Table, is created to store the real efficiencies of the converters taking into account components toler…
Optimizing droop coefficients for minimum cost operation of islanded micro-grids
2017
This paper shows how minimum cost energy management can be carried out for islanded micro-grids considering an expanded state that also includes the system's frequency. Each of the configurations outputted by the energy management system at each hour are indeed technically sound and coherent from the point of view of generation-consumption balancing by exploiting a frequency dependent load flow algorithm. A Glow-worm Swarm Optimization (GSO) algorithm carried out in a 24 hour time frame provides optimized results. A test has been carried out for a residential PV-Storage-Microturbine islanded micro-grid to show the feasibility as well as the efficiency of the proposed approach and results ar…
Smart district energy optimization of flexible energy units for the integration of local energy storage
2017
Several changes are involving electrical power systems, especially distribution networks. For this reason, the actors in charge of managing and operating reliably these grids are facing many technical issues regarding demand and supply balancing, Renewable Energy Sources and Electric Vehicles integration, peak load shaving, etc. In this context, many energy actions have been implemented for providing services to the power system managers by means of prosumers' demand and/or supply flexibility. This study reports the development of a centralized energy management solution for smart grids equipped with local storage devices, RES, consumers and other energy facilities in a district context. Th…
On the hazardous situations due to the presence of HV/MV substations in urban areas
2017
The paper focuses on the hazardous situations that can rise in urban areas in case of earth fault inside a High Voltage/Medium Voltage station. IEEE and IEC/EN Standards and technical documents are examined and discussed, in order to propose some practical guidelines for a safe integration of such installations in contexts characterized by the presence of low voltage systems and not trained persons.
Innovative algorithms for the management of combined RES-BESS systems
2017
The issue of the optimal management of the available energy resources also at end-user level is getting more and more attention. The paper deals with the definition of innovative algorithms for managing electrical storage systems in hybrid photovoltaic and wind plants, also taking into account different pricing periods and a grid emergency condition in which the Utility can request an injection of power by the end-user. Application examples for explaining the operation of the algorithms are presented.