Search results for "System monitoring"
showing 10 items of 16 documents
Un approccio semplificato per il calcolo del load flow nelle smart grids basato su misure distribuite in bassa tensione
2017
I sistemi di misura distribuiti sono alla base delle "smart distribution grids", ove la crescente presenza di generazione distribuita e sistemi di accumulo e la conseguente transizione verso sistemi attivi rendono necessarie funzionalità avanzate di monitoraggio, controllo e gestione delle reti. In tale contesto, un elemento essenziale è l'analisi dei flussi di potenza, che, com'è noto, può essere effettuata tramite algoritmi di load flow, noti il modello della rete e le potenze generate/assorbite nei vari nodi. Per la misura di tali grandezze sulla media tensione (MT), si possono utilizzare diversi strumenti (quali phasor measurement units, smart meters, power quality analyzers), che però …
Un metodo basato su misure distribuite in bassa tensione per il calcolo del load flow nelle smart grids
2016
Con la diffusione della generazione distribuita nei sistemi elettrici di distribuzione e la conseguente loro transizione verso reti attive, è diventato essenziale disporre di opportuni sistemi per il monitoraggio, il controllo e la gestione delle retistesse. In questo ambito, l'unità GMEE di Palermo, in collaborazione con l'ISSIA-CNR e la STMicroelectronics, da alcuni anni si occupa dello sviluppo di sistemi di misura e comunicazione per lo sviluppo delle "smart distribution grids". In particolare, per quanto riguarda il monitoraggio della rete, lo studio è stato focalizzato sull'analisi dei flussi di potenza, che, noti il modello della rete e le potenze generate o assorbite nei vari nodi, …
Real-Time Power Flow Monitoring and Control System for Microgrids Integration in Islanded Scenarios
2019
This article presents an enhanced system for real-time power flow monitoring and control (PFMC) for microgrids integration in medium-voltage (MV) distribution networks. The developed solution includes both system architecture and the monitoring and control algorithms, and it has low implementation and installation costs. It is based on the use of hardware and software solutions previously proposed by the authors, i.e., a distributed measurement, a control and communication architecture, and a supervisory control and data acquisition (SCADA) software, which have been enhanced and integrated for the considered application. The SCADA implements a load flow (LF) algorithm for real-time power fl…
LV Measurement Device Placement for Load Flow Analysis in MV Smart Grids
2016
This paper deals with the issue of measurement device placement for load flow analysis in medium-voltage (MV) distribution networks. The study is carried out using an innovative measurement algorithm for load flow analysis developed by the authors. It is based on low-voltage (LV) load power measurements applied on a backward/forward algorithm for the load flow resolution. The final aim is to identify the most suitable number and placement of the LV measurement points in order to limit the uncertainty on the power flow estimation to a target value. The proposed approach is based on the uncertainty evaluation of the estimated power flows; a sensitivity analysis is performed in order to assess…
Quality Assurance and Support Measures for Solar Cooling on System Level
2016
Abstract Within the IEA SHC Task 48 “Quality assurance and support measures for Solar Cooling” the analysis and evaluation of the systems has been one of the four main focuses. Here the activities are including the lab- and field-based characterization of the systems, the definition and application of performance figures, a guideline for a reliable monitoring procedure including methods for automated error detection and an updated overview on worldwide installed DEC systems including hints and good practice examples. They are furthermore leading to three different easy-to-use tools for solar cooling systems: The LCA tool considers environmental and energetic values for the evaluation, the P…
A simplified approach for load flow analysis in MV smart grids based on LV power measurements
2017
This paper presents a simplified approach for load flow analysis in medium voltage (MV) distribution networks. It is a power summation Backward/Forward (B/F) algorithm, based on measurements of active and reactive powers at low voltage (LV) side of MV/LV distribution substations. The proposed solution allows achieving good accuracy, computational efficiency and fast convergence. In order to verify the algorithm performances, simulation studies are carried out in the case of a real test system, i.e. the distribution grid of Favignana Island (Mediterranean Sea, Italy). The compatibility between simulations results and power measurements at the MV bus bars of the generating substation shows th…
An Innovative Measurement Approach for Load Flow Analysis in MV Smart Grids
2016
This paper proposes a novel measurement procedure for load flow analysis in medium voltage (MV) smart grids. The new approach is based on power measurements at low voltage (LV) side of MV/LV distribution substations. Such measurements are carried out by means of power quality analyzers. If compared with the load flow methods based on measurements at the MV side, the proposed approach has a lower cost and it offers an equally reliable measurement system. The proposed algorithm takes the basic concept of the current summation backward/forward method; some modifications are introduced to use LV load powers measurements. To this aim, the MV/LV power transformer is properly modeled and taken int…
Influence Of Lateral Load Distributions On Pushover Analysis Effectiveness
2008
The effectiveness of two simple load distributions for pushover analysis recently proposed by the authors is investigated through a comparative study, involving static and dynamic analyses of seismic response of eccentrically braced frames. It is shown that in the upper floors only multimodal pushover procedures provide results close to the dynamic profile, while the proposed load patterns are always conservative in the lower floors. They over-estimate the seismic response less than the uniform distribution, representing a reliable alternative to the uniform or more sophisticated adaptive procedures proposed by seismic codes. © 2008 American Institute of Physics.
Uncertainty evaluation of a Backward/Forward Load Flow algorithm for a MV smart grid
2015
This paper presents the uncertainty evaluation of an innovative measurement algorithm for load flow analysis in MV distribution networks. The measurement procedure is based on Low Voltage (LV) load power measurements applied on a Backward/Forward (B/F) algorithm for the Load Flow (LF) resolution. Furthermore, in the procedure a three phase voltage measurement at the MV generating substation bus-bars is also considered. The accuracy analysis of the LF algorithm is performed in the case of a real load condition in the distribution grid of Ustica island, Italy. The analysis takes into account the uncertainty of the measurement instruments at the LV side of each secondary substation power trans…
A predictive maintenance policy with imperfect monitoring
2010
For many systems,failure is a very dangerous or costly event. To reduce the occurrence of this event,it is necessary to implement a preventive maintenance policy to replace the critical elements before failure.Since elements do not often exhibit incipient faults, they are replaced before a complete exploiting of their useful life.To conjugate the objective of exploiting elements for almost all their useful life with the objective to avoid failure,condition based and,more recently,predictive maintenance policies have been proposed.This paper deals with this topic and proposes a procedure for the computation of the maintenance time that minimizes the global maintenance cost.By adopting a stoc…