Search results for "power system"
showing 10 items of 322 documents
Smart grid integrated green data centres as ancillary service providers
2015
In this paper a review of Green Data Centres facilities to support smart grids operation is proposed. The paper describes the ancillary services a Green Data Centre can provide both in terms of spinning reserve provision and different regulation services. In the application section, a real electrical grid hosting a data centre is considered. The infrastructure is owned by Engineering S.p.A. and is installed in northern Italy. The system has been considered as connected to the MV distribution grid in presence of other renewable energy sources. The impact of possible power management operations over the considered data centre has been studied by means of a simulation software and the spinning…
Optimal Energy Management of Smart Grids With Plug-In Hybrid Electric Vehicles
2015
In this paper, smart grids based on Renewable Energy Sources are addressed. An Italian case study which has been developed in the frame of the research project i-NEXT (Innovation for green Energy and eXchange in Transportation) is presented. Storage elements are included. Electric and fuel cell powered vehicles' charging stations are here included as local loads. In this paper, power management algorithms and the control logic are described. The control subsystem aims at an efficient management of the involved renewable energy sources avoiding faults in the power system and ensuring a fully functional supply of local loads. A “Service Center” software collecting data from renewable sources,…
GA-ANN for Short-Term Wind Energy Prediction
2011
Wind turbine power output is totally intermittent in the nature. For grid connected wind turbine generators, power system operators (transmission system operators) need reliable and robust wind power forecasting system. Rapid changes in the wind generation relative to the load require proper energy management system to maintain the power system stability and of course to balance the power generation, frequency, voltage regulation within the statutory limits. Accurate wind energy forecasting helps the power system transmission system operators in anticipating rapid changes in wind turbine power output with respect to load and helps in making decision not only for optimum energy management bu…
Arc Fault Detection Method Based on CZT Low-Frequency Harmonic Current Analysis
2017
This paper presents a method for the detection of series arc faults in electrical circuits, which has been developed starting from an experimental characterization of the arc fault phenomenon and an arcing current study in several test conditions. Starting from this, the authors have found that is it possible to suitably detect arc faults by means of a high-resolution low-frequency harmonic analysis of current signal, based on chirp zeta transform, and a proper set of indicators. The proposed method effectiveness is shown by means of experimental tests, which were carried in both arcing and nonarcing conditions and in the presence of different loads, chosen according to the UL 1699 standard…
Charging management of grid integrated battery for overcoming the intermittency of RE sources
2016
Grid integration of distributed generation (DG) systems with energy storage system can help not only in increasing the more penetration of DG systems into the network but it is also going to help in improving the power system dynamics, stability and control as well as helping in demand side management. In this work, a method for integrating an energy storage with the grid which can provide the prescribed active and reactive power to the grid is presented. The main objective is to ensure a high state of charge (SOC) of the battery with the innovative control system for taking part in power system control. Active and reactive power dispatching using a bi-directional DC-DC converters and a vol…
Harmonic mitigation of a grid-connected photovoltaic system using shunt active filter
2017
Conventional LC filters cannot compensate effectively harmonics due to non-linear loads in a grid-connected photovoltaic (PV) system. Thus, active power filters (APF) are introduced due to its characteristics and performances, for compensation of harmonics from non-linear loads in the grid-connected photovoltaic (PV) system. This work presents a three-phase voltage-fed shunt active power filter implementation to mitigate the harmonics in which the filter control system focuses on generating reference source current for compensating harmonic effects from non-linear loads. Furthermore, the developed model is verified with an experimental data from a nonlinear load.
Load management for voltage security using probabilistic fuzzy decision tree method
2016
During contingency, load management is most important in planning, monitoring and controlling of power system. In transmission system, there is limit for controlling the reactive power in large size power network. In order to manage heavy loading on transmission, load management is necessary to avoid voltage collapse. This paper presents a methodology for load management considering voltage security assessment using probabilistic fuzzy decision tree (PFDT) technique. By using probabilistic fuzzy decision tree method, the load management is calculated in optimal manner in real time and insecure operating conditions are observed. With the help of this method, a real time load management plan …
Reassessment of voltage stability for distribution networks in presence of DG
2016
There is a growing interest in integrating renewable energy based distributed generation (DG) in the electrical power distribution networks. The installation of DG units at distribution level impacts critically the planning and operation characteristics of the network. The type, location, number and capacity of the integrated DGs affects system behavior and performance. In this paper the effect of installing new DGs on the distribution network voltage stability is studied. The optimal location of the newly installed DGs are decided based on the Power Stability Index (PSI) and Voltage Stability Index (VSI). Moreover, Voltage Stability Margin (VSM) of the interconnected DG distribution networ…
Battery storage systems for peak load shaving applications: Part 1: Operating strategy and modification of the power diagram
2016
Battery Energy Storage Systems (BESSs) are gaining more and more attention in the current global energy landscape, thanks to some peculiar characteristics such as the versatility, modularity, scalability, fast response time, etc. BESSs can advantageously be used in the ancillary services market, in order to provide all the services necessary to ensure the stability and the reliability of the power system. Among other applications, BESS can also be used to shift electricity demand from on-peak to off-peak periods, also contributing to relieve peak demand charges, thus ensuring a saving for the customers. The BESS is charged when the electricity prices are the lowest (during the night) and di…
A PC-based instrument for harmonics and interharmonics measurement in power supply systems
2004
Abstract Growing interest on power quality has led international working groups to define new standards for testing and measurement techniques to apply to power systems. Special attention has been paid to harmonic and interharmonic measurements. Here, the authors introduce a PC-based instrument capable of synchronising sampling frequency with fundamental frequency in order to perform on-line voltage or current distortion analysis. The instrument has been developed in accordance with currently available standards and international documents, IEC 61000-4-7 Ed. 2002, IEC 61000-4-30 Ed. 2003, Draft Guide IEEE P1159.1 Ed. 2003 and limits given by IEC 61000 Part. 3. A detailed description of the …