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Author: n.sene
Type: Publication
Date: 2015-10-22

Fault Current Limiters in Industrial Power Systems

Description:
The concept of saturable core fault current limiter (FCL) is relatively known nowadays. It usually consists of two reversely magnetized cores per phase to effectively limit the fault current passively... see more and immediately upon its inception. In this paper prospects of application of fault current limiters in industrial power systems will be considered. Industrial power systems (distribution networks) are widespread and include a number of various electrical appliances. The power systems development (addition of new power plants, interconnections, etc.) may lead to more intense short circuit currents at the fault location. Furthermore, industrial systems may possess on-site generation which can increase fault current levels as well. All these factors might require appropriate upgrades of industrial system electrical equipment (especially switchgear) or special operating procedures (for instance avoiding parallel operation). Another alternative is the installation of fault current limiters. In this light, a series of simulations were carried out in order to observe the impact of fault current limiters on short circuit currents in an industrial power system using the EMTP-RV software program.

Keywords: saturable core fault current limiter (FCL), industrial power system, induction machine, EMTP; fault current analysis, medium voltage

Tag(s): saturable core fault current limiter (FCL), industrial power system, induction machine, EMTP; fault current analysis, medium voltage

Author: n.sene
Type: Publication
Date: 2015-04-02

Selection of MV/LV Transformers to be Protected by Surge Arresters against Indirect Lightning Overvoltages

Description:
The papers addresses the problem of locating surge protective devices in a medium voltage distribution network by means of an accurate computer model for the calculation of lightning induced overvolta... see moreges and a Monte Carlo statistical procedure. The indirect lightning performance of small network cells of different configuration are evaluated and used as a benchmark for the validation of the surge arrester locations provided by a genetic algorithm procedure. The obtained results appear useful for the lightning protection design of networks
with complex topology.

Authors: Alberto Borghetti, Fabio Napolitano, Carlo Alberto Nucci, Fabio Tossani, Gilnei J. G. Dos Santos, Donorvan R. Fagundes, Gustavo P. Lopes, Manuel L. B. Martinez

2014 International Conference on Lightning Protection (ICLP), Shanghai, China

Tag(s): distribution network; surge arresters; lightning protection.

Author: n.sene
Type: Publication
Date: 2015-04-02

lCT -power Co-simulation Platform for the Analysis of Communication-based Volt/Var Optimization in Distribution Feeders

Description:
The paper presents an ICT and power co-simulation platform for the analysis of the voltlvar control and relevant optimization in medium voltage distribution feeders, achieved by means of a system of d... see moreistributed controllers coordinated via a shared band-limited digital communication network. The platform has been built by realizing the interface between two specific simulation environments:
the Electromagnetic Transient Program EMTP-RV and the communication network simulator Opnet Modeller. The preliminary results provide basic indications on the expected performances of the considered communication-based strategies for ditJerent tratlic congestion levels and load/generation dynamic variations.

Authors: Riccardo Bottura, Alberto Borghetti, Fabio Napolitano, Carlo Alberto Nucci

Tag(s): Co-simulation, Networked Control Systems, Power distribution feeders, Voltlvar optimization.

Author: n.sene
Type: Publication
Date: 2015-04-02

Simulation of the Volt/Var Control in Distribution Feeders by Means of a Networked Multiagent System

Description:
The adoption of networked multiagent systems (MAS) has been recently proposed for the solution of the volt/var control (VVC) problem in distribution feeders. However, constraints and limitations due t... see moreo the communication network, to the dynamic behavior of power system components and regulators, as well as to the measurement uncertainties of the adopted sensors need to be specifically analyzed for the design of the MAS. For this purpose, a cosimulation platform has been built by the integration of two simulation tools:
1) the electromagnetic transient program EMTP-rv; and 2) the communication network simulator Riverbed-OPNET Modeler. This paper presents the modeling and simulation of an asynchronous leaderless MAS-based approach that coordinates the reactive power outputs of a set of power compensators equipped with phasor measurement units via a shared band-limited packet-switched digital communication network. The effects of communication network latency and packet loss on the VVC performances are analyzed for two unbalanced IEEE Test feeders equipped with on-load tap changer transformers. The paper compares the results obtained by using a transmission control protocol (TCP) and a user datagram protocol (UDP), for different levels of background traffic (BT) and different packet discard ratios (PDRs) in the communication links.

Authors: Riccardo Bottura, Student Member, IEEE, and Alberto Borghetti, Senior Member, IEEE

IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS, VOL. 10, NO. 4, NOVEMBER 2014

Tag(s): Cosimulation, medium voltage distribution feeders, multiagent systems (MAS), networked control systems (NCS), phasor measurement unit (PMU), volt/var control (VVC).

Author: n.sene
Type: Publication
Date: 2015-04-01

VOLTAGE TRANSIENTS IN A DISTRIBUTION NETWORK CORRELATED WITH EVENTS IDENTIFIED BY A LIGHTNING LOCATION SYSTEM

Description:
Monitoring units for the measurement of high frequency voltage transients have been in operation at three different busses of an Italian medium voltage (MV) distribution feeder, mainly composed by ove... see morerhead lines, in March 2007 – August 2008. The feeder is located in a region characterized by a high ground flash density value (4 flashes/km2/yr); many of the recorded voltage transients may be correlated with the lightning events detected for the same region by the Lightning Location System (LLS) CESISIRF. The paper presents some experimental results obtained using the monitoring units and their comparison with computer results obtained using a LIOV-EMTP model of the considered MV feeder. A procedure aimed at achieving the best fit between measurements and calculations, which takes into account the uncertainties associated with LLS data, is also presented.

Authors:A. Borghetti, F. Napolitano, C.A. Nucci, M. Paolone, M. Bernardi, W. Schulz

X International Symposium on Lightning Protection, 9th-13th November, 2009 – Curitiba, Brazil

Tag(s): Lightning, distribution network, LIOV, EMTP