• Energy Research

At the moment, power systems all over the world are still facing, with new tools at disposal, old problems, made now more urgent due to the increasing amount of power transactions and to the active presence of many new operators of the electricity market. While from the technical point of view the dynamic security assessment and control tools are conceptually the same as those developed in the past, the electricity market changes the way they ought to be used and exploited as well as most of all economic conditions under which the single control actions can be adopted. The paper shows the improvement that, in the dynamic security assessment and control tools, the Italian transmission system operator has made during the last years and describes the state of the art of the practices adopted in the operational planning and in the real time operation of the Italian power system. Moreover, the paper presents the most recent arrangements made within the Italian electricity market regarding some tools and control actions that could be adopted to guarantee the dynamic security. The most important issues highlighted by the 2003 blackout from the point of view of procedures and of the legal and standard framework are also described.

At the moment, power systems all over the world are still facing, with new tools at disposal, old problems, made now more urgent due to the increasing amount of power transactions and to the active presence of many new operators of the electricity market. While from the technical point of view the dynamic security assessment and control tools are conceptually the same as those developed in the past, the electricity market changes the way they ought to be used and exploited as well as most of all economic conditions under which the single control actions can be adopted. The paper shows the improvement that, in the dynamic security assessment and control tools, the Italian transmission system operator has made during the last years and describes the state of the art of the practices adopted in the operational planning and in the real time operation of the Italian power system. Moreover, the paper presents the most recent arrangements made within the Italian electricity market regarding some tools and control actions that could be adopted to guarantee the dynamic security. The most important issues highlighted by the 2003 blackout from the point of view of procedures and of the legal and standard framework are also described.

Summary form only given. The electricity markets are changing the power system operation. The increasing power exchanges make it necessary to operate the transmission grids closer and closer to security limits. A problem posed to power system engineers is therefore to find a suitable methodology to combine the results of both steady state and dynamic tools: this can reduce the overall computational effort and the difficulty in the interpretation of results. The paper presents a detailed comparison of the computations that can be performed through steady state and dynamic procedures regarding the power system security. In particular, the analysis of the loadability margins available on the corridor between the Italian power system and the UCTE (Union for the Coordination of the Transmission of Electricity) grids is carried out using both steady state and dynamic tools; the results are compared, pointing out also the security enhancement given by a hierarchical voltage control.

Summary form only given. The electricity markets are changing the power system operation. The increasing power exchanges make it necessary to operate the transmission grids closer and closer to security limits. A problem posed to power system engineers is therefore to find a suitable methodology to combine the results of both steady state and dynamic tools: this can reduce the overall computational effort and the difficulty in the interpretation of results. The paper presents a detailed comparison of the computations that can be performed through steady state and dynamic procedures regarding the power system security. In particular, the analysis of the loadability margins available on the corridor between the Italian power system and the UCTE (Union for the Coordination of the Transmission of Electricity) grids is carried out using both steady state and dynamic tools; the results are compared, pointing out also the security enhancement given by a hierarchical voltage control.

As renewable energy sources are integrated into power systems, the complexity of their management increases. For the analysis of modern power systems, clustering algorithms have become indispensable tools. The representation of an electric power transmission system involves conceptualizing it as a graph—a mathematical structure depicting a set of nodes and edges. In the context of power systems, these nodes correspond to buses, and the edges represent branches. Weighting may be assigned to the edges to denote the strength of their connections. In this paper, spectral clustering and hierarchical agglomerative clustering have been employed to analyze the Italian transmission network. Spectral clustering relies on the eigenvalues and eigenvectors derived from the Laplacian matrix associated with the network. The hierarchical agglomerative clustering, based on Thévenin impedance to define the distances, merges the two closest clusters at each step. The primary objective of this research is to identify distinct areas within the network based solely on its topology. In pursuit of this goal, admittances and Thévenin impedances have been employed as weights in the graph representation. By utilizing these approaches, the research aims at uncovering meaningful structures and patterns within the power transmission system based on the inherent connectivity and strength of the network elements. The techniques have been used on two real network models to demonstrate the performance of the algorithms with different grid configurations.

As renewable energy sources are integrated into power systems, the complexity of their management increases. For the analysis of modern power systems, clustering algorithms have become indispensable tools. The representation of an electric power transmission system involves conceptualizing it as a graph—a mathematical structure depicting a set of nodes and edges. In the context of power systems, these nodes correspond to buses, and the edges represent branches. Weighting may be assigned to the edges to denote the strength of their connections. In this paper, spectral clustering and hierarchical agglomerative clustering have been employed to analyze the Italian transmission network. Spectral clustering relies on the eigenvalues and eigenvectors derived from the Laplacian matrix associated with the network. The hierarchical agglomerative clustering, based on Thévenin impedance to define the distances, merges the two closest clusters at each step. The primary objective of this research is to identify distinct areas within the network based solely on its topology. In pursuit of this goal, admittances and Thévenin impedances have been employed as weights in the graph representation. By utilizing these approaches, the research aims at uncovering meaningful structures and patterns within the power transmission system based on the inherent connectivity and strength of the network elements. The techniques have been used on two real network models to demonstrate the performance of the algorithms with different grid configurations.

This study presents the assumptions and strategies for the practical implementation of the dynamic mode decomposition approach in the wide-area monitoring system of the Italian transmission system operator, Terna. The procedure setup aims to detect poorly damped interarea oscillations of power systems. Dynamic mode decomposition is a data-driven technique that has gained increasing attention in different fields; the proposed implementation can both characterize the oscillatory modes and identify the most influenced areas. This study presents the results of its practical implementation and operational experience in power system monitoring. It focuses on the main characteristics and solutions identified to reliably monitor the interarea electromechanical modes of the interconnected European power system. Moreover, conditions to issue an appropriate alarm in case of critical operating conditions are described. The effectiveness of the proposed approach is validated by its application in three case studies: a critical oscillatory event and a short-circuit event that occurred in the Italian power system in the previous years, and a 15-min time interval of normal grid operation recorded in March 2021.

This study presents the assumptions and strategies for the practical implementation of the dynamic mode decomposition approach in the wide-area monitoring system of the Italian transmission system operator, Terna. The procedure setup aims to detect poorly damped interarea oscillations of power systems. Dynamic mode decomposition is a data-driven technique that has gained increasing attention in different fields; the proposed implementation can both characterize the oscillatory modes and identify the most influenced areas. This study presents the results of its practical implementation and operational experience in power system monitoring. It focuses on the main characteristics and solutions identified to reliably monitor the interarea electromechanical modes of the interconnected European power system. Moreover, conditions to issue an appropriate alarm in case of critical operating conditions are described. The effectiveness of the proposed approach is validated by its application in three case studies: a critical oscillatory event and a short-circuit event that occurred in the Italian power system in the previous years, and a 15-min time interval of normal grid operation recorded in March 2021.

This work proposes a new Energy Management System (EMS) for Battery Energy Storage Systems (BESS). The goal is to make a BESS profitable in the new environment considering massive use of batteries that can be foreseen in the next future, due to the predictive increase of clean energy resources. The developed EMS considers two levels of optimization. The first level models the participation of the BESS in an Ancillary Service Market and schedules the BESS. The second level, the most innovative, is responsible for optimally distributing the power set-points obtained previously among the various battery banks considering, in addition to the battery aging, also the different efficiencies of battery banks, converters, and transformers. Moreover, this second-level manages both active and reactive power flows, and losses. Both optimization algorithms have been modeled as Mixed Integer Linear Programming (MILP) and implemented in GAMS using CPLEX as a solver. The results are encouraging: compared with the common industrial practice in which the load profile is equally shared among the individual batteries within a BESS, the two new proposed EMS strategies guarantee for a long period of operation (10-years) a consistent reduction in the number of batteries replacement (around 47%), thus ensuring significant cost savings. Moreover, the proposed BESS model accurately approximates the real physical behavior of the system, leading to an average error in State-of Energy (SoE) evaluation below 0.6%, which is almost one order of magnitude lower than the ones obtained by simpler models from literature with degradation only SoE-dependent.