Big changes are taking places in the electrical networks all around the world. The introduction of renewable resources, the growing power demand, the increase of the quality standards, the obsolescence of the actual grid and the continuous increase of the prices of primary energy sources impose a refurbishment and a significant expansion of the transmission network. Using of modern “smart” technologies and an optimized management of each phase of the grid planning have become daily issues for Transmission System Operators (TSO). The Republic of Ireland has launched a plan which envisages an exponential growth of the Renewable Energy Sources (RES) penetration, in particular wind energy, in the grid, aiming to obtain a green energy production equal to 40% by 2020. Big investments are being made to reach this ambitious goal, assisted with leading edge procedures at the planning stage. The Irish TSO, EirGrid, has started to use a tool, ESPAUT, which is able to plan the electric grid expansion in an optimal way from both the technical and the economic point of views. Once the grid structure has been fixed, another tool, AC ESPAUT, optimizes the reactive allocation in the electric grid, considering a multi-objective function. In this work, a new approach to the problem of grid planning is proposed from the operational perspective. The tool AC ESPAUT is used in its potentialities for sequential analyses on a daily period of time. Results allow to comprehend how an electrical system can be managed in an optimal way, with a general control on its principal aspects. The algorithm permits also to compare different transmission technologies, such as OverHead Lines (OHL), UnderGround Cables (UGC) and High Voltage Direct Current lines (HVDC), from both a technical and an economical point of view. A particular attention is given to UGC, showing how a “smart” management produces benefits for the entire grid. Monitoring the cable conditions in real time, a dynamic management is possible, thus resulting in an increase of the transmission capacity of the cable itself, helping to solve critical situations as congestions and contingencies. The thermal-electrical dynamic of cables is analysed from the point of view the TSO to obtain the major economic benefits. The algorithm is applied on a small size grid for studying purposes and, at a later stage, on the Irish transmission grid.
Grandi cambiamenti sono in corso nelle reti elettriche di tutto il mondo. L'introduzione delle energie rinnovabili, il crescente fabbisogno di energia elettrica, l'innalzamento degli standard qualitativi, l'obsolescenza della rete esistente e la continua crescita dei prezzi delle fonti primarie di energia impongono un rinnovamento ed un'espansione significativa della rete di trasmissione. L'uso di moderne tecnologie "smart" e una gestione ottimizzata di ogni fase di pianificazione della rete elettrica sono diventati problemi quotidiani per i Transmission System Operator (TSO) mondiali. La Repubblica d'Irlanda ha varato un piano che prevede una crescita esponenziale della penetrazione di fonti rinnovabili, in particolare di energia eolica, nella rete, con l'obiettivo di una produzione di energia “verde” pari al 40% del totale entro il 2020. Grandi investimenti sono in atto per raggiungere questo ambizioso traguardo, coadiuvati da procedure all'avanguardia in fase di pianificazione. Il gestore di rete irlandese, EirGrid, ha iniziato ad utilizzare un tool, ESPAUT, che è in grado di pianificare l’espansione della rete elettrica in modo ottimale dal punto di vista sia tecnico che economico. Una volta fissata la struttura di rete, un secondo tool, AC ESPAUT è in grado di ottimizzare l’allocazione reattiva nella rete elettrica attraverso la considerazione di una funzione multi-obiettivo. In questo lavoro, viene proposto un nuovo approccio al problema della pianificazione delle risorse di potenza reattiva dal punto vista operazionale. Il tool AC ESPAUT viene sfruttato nelle sue potenzialità per analisi di tipo sequenziale su un arco di tempo giornaliero. I risultati ottenuti permettono di comprendere come un sistema elettrico possa essere gestito in modo ottimale, con un controllo generale nei suoi principali aspetti. L'algoritmo permette anche di confrontare dal punto di vista sia tecnico sia economico differenti tecnologie di trasmissione quali linee aree, cavi interrati e collegamenti in corrente continua. Una particolare attenzione viene data ai cavi interrati, mostrando come una loro gestione "smart" apporti benefici generali per tutta la rete. Monitorando le condizioni del cavo in tempo reale, è possibile una sua gestione dinamica che permette di aumentare la capacità di trasporto del cavo stesso, aiutando a risolvere situazioni critiche quali congestioni e guasti. La dinamica termico-elettrica dei cavi viene analizzata dal punto di vista del gestore elettrico per poter trarne il massimo beneficio economico. Applicazioni dell’algoritmo sono condotte su una rete di piccole dimensioni a scopo di studio e, successivamente, sulla rete nazionale irlandese.
A procedure to evaluate the impact of transmission technologies and dynamic cable rating on power systems
RADAELLI, LUCA PAOLO
2012/2013
Abstract
Big changes are taking places in the electrical networks all around the world. The introduction of renewable resources, the growing power demand, the increase of the quality standards, the obsolescence of the actual grid and the continuous increase of the prices of primary energy sources impose a refurbishment and a significant expansion of the transmission network. Using of modern “smart” technologies and an optimized management of each phase of the grid planning have become daily issues for Transmission System Operators (TSO). The Republic of Ireland has launched a plan which envisages an exponential growth of the Renewable Energy Sources (RES) penetration, in particular wind energy, in the grid, aiming to obtain a green energy production equal to 40% by 2020. Big investments are being made to reach this ambitious goal, assisted with leading edge procedures at the planning stage. The Irish TSO, EirGrid, has started to use a tool, ESPAUT, which is able to plan the electric grid expansion in an optimal way from both the technical and the economic point of views. Once the grid structure has been fixed, another tool, AC ESPAUT, optimizes the reactive allocation in the electric grid, considering a multi-objective function. In this work, a new approach to the problem of grid planning is proposed from the operational perspective. The tool AC ESPAUT is used in its potentialities for sequential analyses on a daily period of time. Results allow to comprehend how an electrical system can be managed in an optimal way, with a general control on its principal aspects. The algorithm permits also to compare different transmission technologies, such as OverHead Lines (OHL), UnderGround Cables (UGC) and High Voltage Direct Current lines (HVDC), from both a technical and an economical point of view. A particular attention is given to UGC, showing how a “smart” management produces benefits for the entire grid. Monitoring the cable conditions in real time, a dynamic management is possible, thus resulting in an increase of the transmission capacity of the cable itself, helping to solve critical situations as congestions and contingencies. The thermal-electrical dynamic of cables is analysed from the point of view the TSO to obtain the major economic benefits. The algorithm is applied on a small size grid for studying purposes and, at a later stage, on the Irish transmission grid.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/88644