Search results for "Reliability"
showing 10 items of 1563 documents
Battery Models for Battery Powered Applications: A Comparative Study
2020
Battery models have gained great importance in recent years, thanks to the increasingly massive penetration of electric vehicles in the transport market. Accurate battery models are needed to evaluate battery performances and design an efficient battery management system. Different modeling approaches are available in literature, each one with its own advantages and disadvantages. In general, more complex models give accurate results, at the cost of higher computational efforts and time-consuming and costly laboratory testing for parametrization. For these reasons, for early stage evaluation and design of battery management systems, models with simple parameter identification procedures are…
Predicting the Batteries' State of Health in Wireless Sensor Networks Applications
2018
[EN] The lifetime of wireless sensor networks deployments depends strongly on the nodes battery state of health (SoH). It is important to detect promptly those motes whose batteries are affected and degraded by ageing, environmental conditions, failures, etc. There are several parameters that can provide significant information of the battery SoH, such as the number of charge/discharge cycles, the internal resistance, voltage, drained current, temperature, etc. The combination of these parameters can be used to generate analytical models capable of predicting the battery SoH. The generation of these models needs a previous process to collect dense data traces with sampled values of the batt…
Numerical and experimental validation of a LiFePO<inf>4</inf> battery model at steady state and transient operations
2013
In the paper some of the battery models proposed in literature are analysed in order to predict the battery performance and, then, make sure that the Battery Management System (BMS) that is a key component to check and control the status of the batteries within their specified safe operating conditions, works in best conditions. In fact to reach an extended battery lifetime and increase the reliability of the system, is necessary to guarantee an accurate evaluation of the state of the whole stack of batteries to track their operations. Therefore, an accurate battery model that captures the dynamics of the battery is required. Lithium batteries are in particular considered because of their h…
A heuristic approach for optimal operation of grid connected source-battery-load systems
2016
In the paper an optimal management procedure for a system composed of a renewable energy source, storage batteries and a load, permanently connected to a distribution network, is presented. The issue follows two objectives: a) maximum economic benefit for the system, and b) minimum energy exchange with the network. The operation cost of storage facilities, as well as the technical and economic constraints on power exchanges between the system and the network and the technical constraints about charging and discharging cycles of the batteries are considered. The effectiveness of the management procedure is numerically tested and the results are presented.
Decentralized on-site optimization of a battery storage system using one-way communication
2015
Intermittent renewable energy sources (e.g. wind, solar energy systems) have been providing an exponentially growing share of electricity generation. Due to their highly transient and stochastic nature, they pose substantial challenges for power grid operation. Power dispatched from these sources are uncontrolled and do not necessarily coincide with demand; this in turn affects power quality. Hence, extensive demand side management (DSM) is required. DSM relies on flexible loads as well as energy storage facilities. Furthermore, renewable power generation is by its very nature highly distributed and consists of large numbers of small units. These have a substantial effect on traditional pow…
Performance Assessment of Building Integrated Photovoltaic and Battery Energy System: A Case Study of TERI-Retreat Facilty in India
2019
Building integrated photovoltaic (BIPV) with energy storage can play an important role not only in demand side management but also in a micro-grid system in coordination with other distributed generators. The operational analysis of BIPV system and energy storage with contribution to local load profile is needed for its grid connected operation, as well as for integrating it in the micro-grid system. In this work, a typical institution has been selected, where the PV system and energy storage are operated for supplying local load in coordination with the grid. The institutional load profile has been analyzed with essential and non-essential loads for understanding the operation and contribu…
Power Grid Integration and Use-Case Study of Acid-Base Flow Battery Technology
2021
There are many different types of energy storage systems (ESS) available and the functionality that they can provide is extensive. However, each of these solutions come with their own set of drawbacks. The acid-base flow battery (ABFB) technology aims to provide a route to a cheap, clean and safe ESS by means of providing a new kind of energy storage technology based on reversible dissociation of water via bipolar electrodialysis. First, the main characteristics of the ABFB technology are described briefly to highlight its main advantages and drawbacks and define the most-competitive use-case scenarios in which the technology could be applied, as well as analyze the particular characteristi…
Long-term reliability of the Finnish behavioral and emotional rating scale
2015
In previous research, the Finnish version of the Behavioral and Emotional Rating Scale-2 has demonstrated adequate internal consistency, factor structure and convergent validity. The purpose of the present study was to examine the long-term test-retest reliability of the Finnish BERS-2. Youth, parent and teacher BERS-2 ratings were collected once a year for three years in order to assess the stability of scores. All of the correlations were significant and moderate to very large in magnitude. Study limitations, future research and implications were discussed.
Validez factorial de una escala de generatividad en español: ¿otra escala con efectos de método?
2017
Introducción: Erikson (1950) utilizó el término “generatividad” por primera vez y se refiere al estado de adultez en el ciclo de vida, lo que implica procreatividad, productividad y creatividad e impulsa el desarrollo de la propia identidad. Existen varias formas de medir la generatividad como las entrevistas, la observación directa, los estudios de caso o los cuestionarios de autoinforme. El método más utilizado es el autoinforme y, entre las escalas disponibles, una de las más destacadas es la Escala de Generatividad de Loyola (EGL). La EGL es una medida de autoinforme que consta de veinte ítems que miden un factor general de generatividad.Objetivo: este estudio examinó la validez factori…
Digital Resilience to Normal Accidents in High-Reliability Organizations
2021
Digital technologies play a dual role on organizational resilience. On one side, digital systems introduce new technological risks. On the other side, digital systems increase the performances in response to hazardous accidents. Normal Accident Theory (NAT) and High-Reliability Organization (HRO) provide useful ground to explain the dynamics of digital resilience. However, the two theories have been either used as alternatives or with one theory dominating the other. We posit that to fully understand digital resilience we need to integrate NAT and HRO concepts instead of using them in isolation. We conduct a bibliometric analysis to identify major themes and application domains characterizi…