264 research outputs found
Control and optimization methodologies to enable the energy and ancillary services through microgrids
No full textQuesta tesi di dottorato presenta i risultati delle ricerche condotte dall'autore durante le attività triennali del XXXVII ciclo del Dottorato di Ricerca in Ingegneria Elettrica e Informatica.
attività triennali del XXXVII ciclo del Dottorato di Ricerca in Ingegneria Elettrica e dell'Infor- mazione del Politecnico di Bari.
Ingegneria dell'Informazione presso il Politecnico di Bari, Italia. L'obiettivo primario di questa ricerca
è stato quello di sviluppare ed esplorare metodologie di controllo e ottimizzazione per abilitare l'energia e i servizi ausiliari attraverso le microgrid, con l'obiettivo di migliorarne l'affidabilità e la stabilità. Inoltre, la ricerca si è concentrata sulla facilitazione dell'integrazione delle fonti di energia rinnovabile, sulla garanzia di un funzionamento sicuro e stabile, sulla minimizzazione dei costi operativi complessivi del sistema e sul mantenimento dell'inerzia sintetica per ridurre il tasso di variazione della frequenza, il tutto soddisfacendo le richieste del carico. Le metodologie di controllo e ottimizzazione per le microgrid sono state ampiamente studiate, dalla gestione ottimale delle risorse al controllo dinamico dei componenti della microgrid. Questi studi si concentrano principalmente sulle operazioni della microgrid sia in modalità isolata che connessa alla rete. Nell'ambito del quadro proposto, sono state sviluppate metodologie di controllo e ottimizzazione robuste per gestire la risposta alla domanda, abilitare i servizi ausiliari e implementare un controllo gerarchico di alto livello. Queste metodologie affrontano livelli di controllo
livelli di controllo gerarchico, comprendendo le dinamiche a breve termine e la programmazione a lungo termine, e forniscono strategie complete per ottenere un coordinamento ottimale e lo scambio di energia tra multi-microgrid. Inoltre, questi approcci di controllo e ottimizzazione robusti sono stati analizzati per migliorare la regolazione della frequenza e della tensione, consentendo l'inerzia sintetica e tenendo conto delle incertezze del sistema. Per affrontare le sfide legate alle azioni di controllo dei convertitori di potenza, come il controllo della formazione della rete per la regolazione della frequenza, questa tesi introduce un nuovo approccio di controllo variazionale basato sul problema di Bolza modificato. Questo metodo aumenta le capacità di controllo ottimale attivo nei sistemi elettronici di potenza, migliorando significativamente la regolazione della frequenza nelle microgrid. Nel complesso, le metodologie di controllo e ottimizzazione proposte contribuiscono a migliorare l'affidabilità, la sicurezza e la stabilità delle microgrid, riducendo al contempo i costi operativi e le emissioni di gas serra.This doctoral thesis presents the results of the author’s research conducted during the
three-year activities of the XXXVII cycle of the Ph.D Program in Electrical and Infor-
mation Engineering at Politecnico di Bari, Italy. The primary objective of this research
was to develop and explore control and optimization methodologies for enabling energy
and ancillary services through microgrids, with the goal of enhancing their reliability and
stability. Furthermore, the research focused on facilitating the integration of renewable
energy sources, ensuring their secure and stable operation, minimizing overall system op-
erational costs, and maintaining synthetic inertia to reduce the rate of change of frequency,
all while meeting load demands. Control and optimization methodologies for microgrids have been extensively studied, ranging from optimal resource management to the dynamic control of microgrid
components. These studies primarily focus on microgrid operations in both islanded and
grid-connected modes. Within the proposed framework, robust control and optimization
methodologies have been developed to manage demand response, enable ancillary services,
and implement high-level hierarchical control. These methodologies address hierarchical
control levels, encompassing short-term dynamics and long-term scheduling, and provide
comprehensive strategies for achieving optimal coordination and energy trading among
multi-microgrids. Furthermore, these robust control and optimization approaches have
been analyzed to enhance frequency and voltage regulation, enabling the synthetic inertia,
while also accounting for system uncertainties. To tackle challenges related to power
converter control actions, such as grid-forming control for frequency regulation, this thesis
introduces a novel variational control approach based on the modified Bolza problem. This
method enhances active optimal control capabilities in power electronic systems, signifi-
cantly improving frequency regulation in microgrids. Overall, the proposed control and
optimization methodologies contribute to improving the reliability, security, and stability
of microgrids, while also reducing operational costs and greenhouse gas emissions
A novel approach to Dynamic Security Control: an application for Transmission Management
No full textA methodology for treating dynamic optimization problems relevant to dynamic security assessment (DSA) is proposed. This paper starts with an overview on the description of a dynamic optimization problem in the continuous time domain. Through a discretization, a static optimization problem, in the discrete time domain, is obtained. The solution of this problem allows evaluating preventive control actions able to guarantee static and dynamic security of power system. In particular, corrections on bilateral contract power exchanges, through a contract curtailment procedure, are assessed for security-constrained transmission management in a deregulated environment
Strumenti per la valutazione delle competenze. Dai compiti autentici alle rubriche valutative
No full textDal punto di vista ontologico e metodologico la scienza didattica si incardina su tre elementi: la progettazione, la valutazione e la comuni-cazione (Calenda e Milito, 2020). Nello specifico, la valutazione, quale processo attraverso cui si regola l’azione didattica, permette di dar sen-so all’azione stessa, in quanto richiede l’espressione di un giudizio di valore e consente «l’attribuzione e/o il riconoscimento del valore dell’apprendimento entro una cornice di senso, in funzione di uno sco-po di miglioramento, di crescita, di sviluppo della persona» (Tessaro, 2014, p. 78).
Negli ultimi anni, la necessità di superare la concezione nozionisti-ca, inerte e trasmissiva della conoscenza ha traghettato e accompagnato il percorso di affermazione del costrutto di competenza in ambito edu-cativo e scolastico. Per promuovere una didattica, un apprendimento e una valutazione per competenze è necessario inquadrare il concetto di competenza in relazione ai processi di apprendimento che la promuo-vono e la sottendono, rilevando le opportune strategie per permettere la manifestazione ed espressione delle competenze nel contesto formativo e permettendo al processo valutativo di osservarle, rilevarle, sistema-tizzarle, descriverle, qualificarle e certificarle in relazione al quadro normativo vigente.
Alla luce di quanto detto, nel presente capitolo, si analizzerà il pas-saggio dal costrutto complesso della competenza agli strumenti per la valutazione della stessa: i compiti autentici e le rubriche valutative
Optimal load matching of combined CSP and storage power plant
No full textThe aim of this work is to investigate the potential application of a CSP plant to the supply of residential users. In particular, according to an early statistic estimation of solar radiation on the sun-tracking surface, electricity production is assessed. Potentials for supply of a residential electricity load are analyzed in the presence of suitable energy storage device, aiming to optimize operation costs
Optimal Operation of a Semi-urban Network Integrating Electric Vehicles
No full textSmart charging and vehicle to grid technologies have a fundamental role in the integration process of electric vehicles in distribution networks, in order to ensure safe grid operation while coping with electric vehicle needs. This paper is focused on a technical-oriented optimization procedure for the operation of a low voltage semi-urban grid involving electric vehicles, aiming at minimizing grid losses while taking into account line loading and bus voltage technical limits, using linear programming techniques. The study allows to inspect vehicle interactions within grid operation, considering different load profiles and stochastic samples of vehicle usage
A Monte-Carlo based procedure for optimal sizing of integrated electric vehicle supply infrastructure
No full textIn this paper, the concept of Electric Vehicle Supply Infrastructure (EVSI) is introduced, as an integrated microgrid including photovoltaic, energy storage and charging stations, even in vehicle-to-grid configuration, to feed a fleet of electric vehicles. A methodology is proposed for optimal sizing and operating the integrated infrastructure in order to supply plug-in electric vehicles for covering mobility needs. A MonteCarlo procedure is carried out to assess the influence of different PEV usage conditions on EVSI sizing and operation. The proposed approach is applied to a public authority in Italy
A stochastic approach for power and reserve programming in EV-based DC microgrid
No full textThe integration of electric vehicles in power systems through direct current microgrid solutions with renewable sources and storage could enable the vehicle-to-grid technology and the provision of programmable power exchange profiles with the distribution system. The uncertainties in the forecast of photovoltaic power production and in electric vehicle state at parking arrival time implies the need of energy management solutions based on stochastic operation programming. In this paper, day-ahead energy management procedure for a microgrid including internal reserve provision by energy storage and electric vehicles to deal with these uncertainties is proposed. Simulations are carried out on a realistic electric vehicle supply infrastructure with proper vehicle usage
Distribution Network Optimal Operation with Electric Vehicles
No full textThe envisaged diffusion of electric vehicles and of relevant charging points is posing significant challenges on electric power system operation, in order to ensure the provision of charge service without jeopardizing the network functionality. Therefore, the distribution system operator, dealing with increasing electric vehicle charging facility connections, is in charge of individuating the most appropriate ways for electric vehicle integration. In this research paper, a technical-oriented optimization procedure is carried out, considering distribution operator viewpoint in the presence of electric vehicle diffusion, exploring smart charging and vehicle-to-grid facilities to provide loss reduction while satisfying line loading and bus voltage targets. The procedure accounts for stochastic samples of realistic eletric vehicle charging requirements, in terms of time and energy demand, and includes a sensitivity-based network model in the framework of linear programming. The proposed approach is applied to a set of operating conditions of a real-sized MV radial network, inspecting the impact of different electromobility penetration levels and vehicle usages. The analysis points out the interactions of electrc vehicle smart charging and vehicle-to-grid processes on the network and among electric vehicles as well, individuating the possible formation of energy communities while dealing with distribution network operation
Control strategy for regulating reactive power exchange in offshore wind farm
No full textOffshore wind power is spreading rapidly, even in zones where exploitation was considered unprofitable so far. Connection of offshore wind farms to the transmission network presents some challenges that needs be addressed. This paper investigates the effectiveness of exploiting generator power factor control for reactive power exchange regulation. The technical and economical feasibility of this control strategy is assessed and compared with centralized voltage/reactive regulation control. Investigations are carried out on a 300-MW offshore wind farm
Integration of heat production and thermal comfort models in microgrid operation planning
No full textIn this paper, a procedure aiming to integrate a detailed description of a multi-source thermal production system in a microgrid framework is proposed. The approach involves electric energy production and consumption as well. In particular, a bottom-up engineering viewpoint is adopted, involving energy flows interesting user buildings and mass flow rates and temperatures in the thermal supply facility. Different heating production systems, such as CHPs, boilers and solar thermal devices, are considered, as well as heat exchangers, thermal storage and pipe network. The proposed model is therefore embedded in the day-ahead energy management procedure of the microgrid. The optimal operation plan is evaluated by minimizing operation and emission costs over a daily horizon, satisfying electric demand and thermal comfort requirements. Tests are carried out on a model of the experimental microgrid system built at Electric Power System laboratory of Politecnico di Bari
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