Search results for "SISTEMI"

Current and Voltage Behaviour During a Fault in a HV/MV System: Methods and Measurements

2015

When a single line to ground fault happens on the MV side of a HV/MV system, only a small portion of the fault current is injected into the ground by the ground-grid of the faulty substation. In fact the fault current is distributed between grounding electrodes and MV cables sheaths. In systems with isolated neutral or with resonant earthing this may be sufficient to provide safety from electric shock. Experimental measurements were performed on a real MV distribution network: a real single line to ground fault was made and fault currents were measured in the faulty substation and in four neighbouring substations. In this paper the problem of fault current distribution is introduced, the te…

Influence of LV neutral grounding on global earthing systems

2015

International Standards define a Global Earthing System as an earthing net created interconnecting local Earthing Systems (generally through the shield of MV cables and/or bare buried conductors). In Italy, the regulatory authority for electricity and gas requires distributors to guarantee the electrical continuity of LV neutral conductor. This requirement has led to the standard practice of realizing “reinforcement groundings” along the LV neutral conductor path and at users’ delivery cabinet. Moreover, in urban high-load scenarios (prime candidates to be part of a Global Earthing System), it is common that LV distribution scheme creates, through neutral conductors, an effective connection…

Urban Energy Hubs and Microgrids: Smart Energy Planning for Cities

2017

In this chapter, we try to connect the urban design features with energy consumption and consequent pollution parameters. After a review of a selected set of approaches to Urban Energy Systems study with a special focus on electrical power systems, urban energy systems are proposed as networks of multi-source hybrid energy hubs, where different energy flows are collected at the same bus and can be stored, delivered or transformed as needed. Resources at the hub and infrastructures interact with each other; therefore, both definition and boundaries of such energy systems at urban level are difficult to be clearly outlined. Similarly, the possibility to generate new operational models based o…

A multi-agent system reinforcement learning based optimal power flow for islanded microgrids

2016

In this paper, a distributed intelligence algorithm is used to manage the optimal power flow problem in islanded microgrids. The methodology provides a suboptimal solution although the error is limited to a few percent as compared to a centralized approach. The solution algorithm is multi-agent based. According to the method, couples of agents communicate with each other only if the buses where they are located are electrically connected. The overall prizing system required for learning uses a feedback from an approximated model of the network. Based on the latter, a distributed reiforcement learning algorithm is implemented to minimize the joule losses while meeting operational constraints…

An expert system hybrid architecture to support experiment management

2014

Specific expert systems are used for supporting, speeding-up and adding precision to in silico experimentation in many domains. In particular, many experimentalists exhibit a growing interest in workflow management systems for making a pipeline of experiments. Unfortunately, these type of systems does not integrate a systematic approach or a support component for the workflow composition/reuse. For this reason, in this paper we propose a knowledge-based hybrid architecture for designing expert systems that are able to support experiment management. This architecture defines a reference cognitive space and a proper ontology that describe the state of a problem by means of three different per…

Effect of Integrating Photovoltaic Systems on Electrical Network Losses Considering Load Variation

2018

Planning of Distributed Generation (DG) units in the power distribution networks is an important issue, one of the most important considerations that is directly affected by installing DG units is the power losses. Improper allocation of DG units to the grid can lead to a noticeable increase in the power losses. Moreover, the load variation is considered as critical matter when studying the optimal scenario that minimizes the power losses in the network. The aim of this paper is to investigate the effect of integrating photovoltaic (PV) units on the distribution network losses considering load variation. The optimal parameters of the DG units were calculated for the various load demands in …

Deep drawing versus incremental forming processes: A comparative cradle to gate analysis

2012

The evaluation and reduction of the environmental impact of manufacturing processes have become a crucial issue in the last few years, addressing the interest of industrial and academic research towards greener solutions and technologies. Reducing input materials and energy requirements has become an imperative action in the industrial practice. As a matter of fact, strong is the concern on lightweight solutions and technologies for sheet stamping operations especially in the automotive sector. However, the knowledge on how impactful such processes are is still poor. In this paper, a comparison between a traditional deep drawing and an single point incremental forming process is investigate…

VERSO MODELLI ECOLOGICI DI TRASMISSIONE DELLA CONOSCENZA

2006

On the use of SPH for Mechanical Engineering structural analyses: an elastic linear case

2011

Robust dynamic comfort modeling for motorcycle riding

2015

Comfort modeling is considered a prerequisite in motorcycle design, primarily to address safety concerns and to position the product on the market. However, a comprehensive methodology for comfort modeling during the earliest development phases of a motorcycle model is still missing. Anthropometrical variation is the main noise factor to consider in comfort modeling in relation to the unavoidable variability of body segments. However, comfort is a subjective concept influencing riders' choice of motorcycle model. This work is a generalization of the robust ergonomic design methodology aimed at designing products whose ergonomic performance is insensitive to anthropometrical variation. This …