Search results for "Grid"
showing 10 items of 792 documents
Design of a Cleaning Program for a PV Plant Based on Analysis of Energy Losses
2015
Solar photovoltaic (PV) energy has grown significantly over the past few years. However, despite the increase in installed capacity, this energy source still raises important concerns related to the variability of power production. The short-term effects such as cloud shadowing and supply interruptions, as well as long-term effects such as dust accumulation, seasonal variation, and ageing of PV modules, can cause variability of power production. Therefore, the analysis of all the variability sources in order to provide statistically consistent power production data is an important challenge. This study presents a methodology to analyze data from a PV plant in order to have an independent ev…
Assessing travel time-based accessibility to outdoor ice skating fields for children in Helsinki during the COVID-19 pandemic
2022
This paper was written within the research project called “Equality in suburban physical activity environments, YLLI” (in Finnish: Yhdenvertainen liikunnallinen lähiö, YLLI) funded by the Suburban Programme 2020–2022 (in Finnish: Lähiöohjelma 2020–2022, decision number VN/10837/2020). Informal sport is central to Finnish children’s leisure and physical activity time. This paper aims to build a better understanding of the travel time-based accessibility to informal sports facilities, specifically to ice skating fields, for children and adolescents (aged 7–19) in the city of Helsinki. We focused on the winter of 2020–2021 because COVID-19 restrictions on indoor activities resulted in ice skat…
« Présentation d'un outil d'évaluation de l'évolution des processus psychiques au sein d'un dispositif thérapeutique en clinique du traumatisme »
2022
Objectives: Our project consists in the implementation and the evaluation of a care system for children in a child protection NGO in Cambodia. In view of the cultural differences and specificities of the field, taking into account only the symptoms does not seem to sufficiently account for the processes involved within the system. Based on the observation that there is a lack of tools that would allow us to apprehend these processes, our study focused on the creation of a scoring grid for psychological processes that could be used in the humanitarian field and could support clinical practice. Method: During one year, we met ten children confronted with traumatogenic events, within a device …
Exergoeconomics as a Cost-Accounting Method in Thermal Grids with the Presence of Renewable Energy Producers
2022
Thermal grids are efficient, reliable, and sustainable technologies for satisfying the thermal demands of buildings. The capability to operate at a low temperature allows not only for the integration of heat produced by renewable energy sources but also for the storage of surplus electricity from the grid via “power to heat” technologies. Besides, in the future, heat consumers are expected to behave increasingly as “prosumers”, supplying in some periods heat produced by renewable energy plants on site. In this scenario, it is important to propose a method for the cost allocation among producers connected to the grid. In this regard, this paper proposes Exergoeconomic…
IEA EBC Annex83 Positive Energy Districts
2021
At a global level, the need for energy efficiency and an increased share of renewable energy sources is evident, as is the crucial role of cities due to the rapid urbanization rate. As a consequence of this, the research work related to Positive Energy Districts (PED) has accelerated in recent years. A common shared definition, as well as technological approaches or methodological issues related to PEDs are still unclear in this development and a global scientific discussion is needed. The International Energy Agency’s Energy in Buildings and Communities Programme (IEA EBC) Annex 83 is the main platform for this international scientific debate and research. This paper describes the challeng…
Lo strappo al mos maiorum
2021
Following Doxiadis in his idea of mos maiorum linking eye and hand the essay deals with citizens' action in remembering. This is the opposite of Villa Adriana's paradigm. The focus is in the opposition between the ecleticism of Villa Adrina and th eregularuty of Ippodamus grid.
Damping Provision by Different Virtual Synchronous Machine Schemes
2020
The adoption of virtual synchronous machine (VSM) schemes for the control of power converters is gaining more and more attention both in academia and industry. The VSM control strategies fall into the category of grid-forming converter controls, and they are intended for a range of different applications, providing specific services and different kinds of support to the grid. The paper investigates the possibility of damping provision to the system by VSM power converters. Different schemes are considered and compared, showing the opportunity of the investigated solutions through combined modal and time domain analyses. A specific modification of the power synchronization loop is recognized…
Sensitivity Analysis and Frequency Dynamics of Grid-Connected Converters with Virtual Inertia
2021
For the participation in the frequency control of the system, power converters can be controlled with different strategies and methods, sharing the common concept of virtual inertia capability. In this work, a sensitivity analysis of two main categories of converter controls with virtual inertia is presented. The considered schemes are a grid-following current vector control with additional virtual inertia block and a grid-forming control scheme based on virtual synchronous machine concept. A proper basis for the comparison is first assessed providing an analytical correlation between the control parameters of the two schemes. For the two control strategies, the sensitivity analysis of the …
Decoupled control scheme of grid-connected split-source inverters
2017
Grid-connected power conversion systems for renewable energy sources must fulfill several requirements, e.g., the high efficiency, the reduced cost and complexity, and, quite often, the boost capabilities that is usually achieved using a front-end dc–dc boost converter before the inversion stage, leading to a two-stage architecture. Meanwhile, single-stage power conversion systems, which perform the boosting operation within the inversion one, offer some potential advantages, in terms of reducing the complexity and the volume of the whole system. Among several proposed options, the split-source inverter (SSI) has been recently proposed by Abdelhakim et al. as an alternative option with some…