arXiv subjects

Andrea Mazza

Publications and source records attributed to Andrea Mazza.

9 recordsLinked to original sources

arXiv2026

Moisture Effects in Medium-Voltage Underground Distribution Systems: a perspective overview

The distribution system is becoming a fundamental part for enabling the energy transition. The fault causes may be several and of different nature, embracing a variety of specializations. This review aims at providing an integrated overview of moisture effects across underground Medium Voltage (MV) cable systems and their accessories. The study collects both literature contributions and practical experiences derived from distribution system operators and research projects on the topic. The findings highlight that the choice of the insulation material is fundamental for mitigating the various consequences of the moisture ingress, linked to chemical and physical processes, as well as mechanical, thermal, and electrical factors, all of which are analysed in detail in the paper. The paper examines the effects of moisture on different types of materials, both traditional and innovative, and discusses diagnostic techniques to detect moisture ingress from the surrounding environment as well as internally generated moisture. The path towards increasing MV distribution reliability, reducing outages, and support the energy transition with more robust distribution infrastructure, is hence achievable through improving moisture management across design, installation, monitoring, and maintenance.

eess.SY↗

arXiv2026

Due-to-Heatwaves Faults in Urban Distribution System: An Identification Approach

Distribution system faults occurring during heatwaves (HWs) are not all caused by the HW itself: concurrent factors such as asset ageing, mechanical defects, soil contamination, and operational constraints contribute independently. Hence, indiscriminately attributing all HW-period faults to thermal stress overestimates system vulnerability and misleads asset-management decisions. This paper proposes a systematic framework to identify and quantify the subset of summer faults directly attributable to HW occurrences (denoted Due-to-HW faults), by distinguishing them from Due-to-Others faults. HW events are first characterised through the Excess Heat Factor index. A covariance-based attribution criterion is then developed to distinguish faults whose occurrence is statistically consistent with HW-driven thermal mechanisms from those attributable to independent causes. Complementing the attribution framework, a time-delay model is introduced to estimate the lag between the beginning of a HW and fault occurrence by maximising the normalised covariance between hourly temperature series and shifted fault-duration series. Applied to six years of operational data from a real MV distribution network, the simulation results show that Due-to-HW faults constitute a significant yet variable proportion of total summer faults, underscoring the non-negligible impact of HW occurrences on summer fault statistics. Beyond documenting the deterioration of fault rate and Mean Time Between Failures across all seasons, the analysis confirms that Time-Between-Failures distributions depart significantly from the exponential assumption, with direct implications for the applicability of Poisson-based reliability models to distribution systems subject to recurrent HW stress.

eess.SY↗

arXiv2024

Investigation on the Impact of Heat Waves on Distribution System Failures

This paper discusses some aspects referring to the characterization and modelling of the resilience of distribution systems in the presence of heat waves. The aim is to identify the specific features that can lead to more detailed modelling of the impact of heat waves on the failures that happen in distribution systems. In particular, with heat waves there are differences between the cumulative distribution function of the time to failure in practical cases and in the theoretical reference used for reliability analysis. These differences may be considered to refine the resilience models due to heat waves. Examples taken from real cases are illustrated and commented.

eess.SY↗

arXiv2022

Power-to-Gas in a gas and electricity distribution network: a sensitivity analysis of modeling approaches

Power-to-Gas (P2G) has been one of the most frequently discussed technologies in the last few years. This technology allows producing CO2 free fuels. Thanks to its high flexibility, it may offer services to the power system, fostering Variable Renewable Energy Sources (VRES) and the electricity demand match, mitigating the issues related to VRES overproduction. The role of P2G plants connected to the transmission system as flexibility asset has been extensively analyzed in the literature. Conversely, the analysis of these systems used at distribution level has only been dealt with in a few studies: however, in this case critical operation conditions can easily arise, both on electrical and gas infrastructure. This article presents a methodological analysis on the impact of different simulation approaches when P2G is installed at distribution system level. The choice of the most appropriate modeling approaches for electricity and distribution grids is required in order to avoid overestimating or underestimating the potential flexibility that P2G plants connected to distribution networks can offer. The aim of this paper is to understand the impact of different modeling approaches in order to determine whether, and under which conditions, this is acceptable. An illustrative case study has been developed to perform this kind of analysis. The results demonstrated that it is important to take into account the electric distribution network topology, as the performance of P2G plants could be affected by their placement in the network. Neglecting the dynamics of a gas network or the interactions between P2G plant components under a low gas demand condition can lead to an underestimation of the flexibility of the entire system. If the demand for gas is high enough, the use of simplified assumptions that do not consider the dynamics of the gas network and P2G systems may be acceptable.

eess.SY↗

arXiv2021

Techno-economic analysis of Power-to-Gas plants in a gas and electricity distribution network system with high renewable energy penetration

Distributed generation, based on the exploitation of Renewable Energy Sources (RES), has increased in the last few decades to limit anthropogenic carbon dioxide emissions, and this trend will increase in the future. However, RES generation is not dispatchable, and an increasing share of RES may lead to inefficiencies and even problems for the electricity network. Flexible resources are needed to handle RES generation in order to support the delicate electricity generation and demand balance. Energy conversion technologies (P2X, Power to X) allow the flexibility of energy systems to be increased. These technologies make a connection between different energy sectors (e.g., electricity and gas) possible, and thus create new synergies within an overall multi energy system. This paper analyzes how the P2G technology can be used at the distribution network level (both gas and electricity) to optimize the use of RES. In fact, in order to coordinate P2X resources, it is necessary to take into account the whole multi energy scenario, and not just the electrical side: it therefore becomes fundamental to recognize the pros and cons that Balancing Service Providers (BSPs), composed of a number of P2G plants (representing the Balancing Responsible Providers, BRPs), may have when offering services to an electricity network. Moreover, the convenience of the decarbonization of the gas grid has been evaluated through the calculation of the levelized cost of Synthetic Natural Gas (LCSNG) for cost scenarios for the years 2030 and 2050, considering different assumptions about the cost of the surplus utilization of RES. The results show that LCSNG may vary from 47 to 319 EURO/MWh, according to the different configurations, i.e., only in the best case scenario is the SNG cost comparable with the cost of natural gas, and hence does the P2G technology result to be profitable

eess.SY↗

arXiv2021

Evaluation of the impact of Heat-Wave on Distribution System Resilience

This paper presents the findings about the impact of heat waves on a real urban distribution system. A data-driven methodology is proposed to simulate the portion of faults that can be associated to normal conditions (and hence to reliability) and the portion correlated to the heat wave occurrence. Based on real data collected in the years 2012-2017, the fault rates associated to reliability and resilience have been calculated and then used to feed a Monte Carlo simulation aiming to manage the uncertainty in the fault occurrence. Finally, based on the Italian legislation, the benefits deriving by the substitution of the faulted portion of the system have been calculated.

physics.soc-ph↗

arXiv2020

Metaheuristic optimization of power and energy systems: underlying principles and main issues of the 'rush to heuristics'

In the power and energy systems area, a progressive increase of literature contributions containing applications of metaheuristic algorithms is occurring. In many cases, these applications are merely aimed at proposing the testing of an existing metaheuristic algorithm on a specific problem, claiming that the proposed method is better than other methods based on weak comparisons. This 'rush to heuristics' does not happen in the evolutionary computation domain, where the rules for setting up rigorous comparisons are stricter, but are typical of the domains of application of the metaheuristics. This paper considers the applications to power and energy systems, and aims at providing a comprehensive view of the main issues concerning the use of metaheuristics for global optimization problems. A set of underlying principles that characterize the metaheuristic algorithms is presented. The customization of metaheuristic algorithms to fit the constraints of specific problems is discussed. Some weaknesses and pitfalls found in literature contributions are identified, and specific guidelines are provided on how to prepare sound contributions on the application of metaheuristic algorithms to specific problems.

cs.AI↗

arXiv2019

New insights for setting up contractual options for demand side flexibility

This paper exploits the Duration-of-Use of the demand patterns as a key concept for dealing with demand side flexibility. Starting from the consideration that fine-grained energy metering is not used at the point of supply of the electricity consumers, i.e., the granularity of the energy measured (at time steps of 15 minutes, 30 minutes or one hour), the event-based energy metering (EDM) is indicated as a viable option to provides a very detailed reconstruction of the demand patterns. The use of EDM enables high-quality tracking of the demand peaks with a reduced number of data with respect to the ones needed to measure energy at regular time steps for reaching a similar peak tracking capability. From the EDM outcomes, a new class of options for setting up tariffs or contracts for flexibility, based on the demand duration curve, is envisioned.

eess.SY↗

arXiv2019

Heuristic Optimization of Electrical Energy Systems: Refined Metrics to Compare the Solutions

Many optimization problems admit a number of local optima, among which there is the global optimum. For these problems, various heuristic optimization methods have been proposed. Comparing the results of these solvers requires the definition of suitable metrics. In the electrical energy systems literature, simple metrics such as best value obtained, the mean value, the median or the standard deviation of the solutions are still used. However, the comparisons carried out with these metrics are rather weak, and on these bases a somehow uncontrolled proliferation of heuristic solvers is taking place. This paper addresses the overall issue of understanding the reasons of this proliferation, showing a conceptual scheme that indicates how the assessment of the best solver may result in the unlimited formulation of new solvers. Moreover, this paper shows how the use of more refined metrics defined to compare the optimization result, associated with the definition of appropriate benchmarks, may make the comparisons among the solvers more robust. The proposed metrics are based on the concept of first-order stochastic dominance and are defined for the cases in which: (i) the globally optimal solution can be found (for testing purposes); and (ii) the number of possible solutions is so large that practically it cannot be guaranteed that the global optimum has been found. Illustrative examples are provided for a typical problem in the electrical energy systems area-distribution network reconfiguration. The conceptual results obtained are generally valid to compare the results of other optimization problems.

cs.AI↗