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
Description:
Unplanned power system islanding is usually seen as a major risky operating condition and specific countermeasures are applied in order to avoid it. However the capability of voluntary disconnection f... see morerom the external grid and autonomous operation is often a requirement for some industrial power systems and power plants. The panel session at the 2012 IEEE Innovative Smart Grid Technologies Conference on
“Power system islands, autonomous microgrids and relevant instrumentation” aims at providing an occasion to exchange ideas and experiences in order to envisage situations in which voluntary power system islanding may be useful and to define the instrumentation required for a reliable operation in islanded conditions. This paper, provided by the organizers, reviews some activities recently carried out on this topic at their institution.
Description:
Due to the necessity of developing analysis tools in the integrated ICT and power system domain, this paper describes and compares the architecture and configuration of two different ITC-power system ... see moreco-simulation approaches called SITL (System in the Loop) and HLA (High Level Architecture) Co-simulation platforms. Both platforms make use of the communication network simulator OPNET (Optimum Network Performance). As indicated by the names, the former operates in real time, in order to perform SITL simulations, whilst the latter is based on the HLA interface between OPNET and the power network simulation environment EMTP-rv (Electromagnetic Transient Program). We provide several details on their implementation and present their features by means of the results obtained for two test cases. The paper aims at clarifying the type of analysis that can be effectively carried out by using the two different platforms.
Authors: Riccardo Bottura, Davood Babazadeh, Kun Zhu, Alberto Borghetti, Lars Nordström, Carlo Alberto Nucci
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
Description:
The paper presents a procedure for parameter identification along with its application to the model of a combined cycle power plant that includes the surrounding electrical network, built for the anal... see moreysis of islanding maneuvers transients. The paper illustrates both the power system computer model, implemented within the EMTP-RV simulation environment, and the developed identification procedure based on the interface between the developed model and Matlab. The parameter identification procedure is applied to experimental transient recordings that make reference to a similar power plant.
Authors: A. Borghetti, C.A. Nucci, M. Paolone, M. Bosetti
Description:
The switching of medium voltage electrical motors is typically realized by means of vacuum circuit breakers (VCBs) essentially in view of their elevated number of switching cycles. As known, switching... see more of VCBs generates important transient recovery voltages (TRVs)
that need to be properly evaluated in both VCB sizing and in the power system insulation coordination. As large medium voltage electrical motors are installed into plants typically controlled by means of Supervisory Control And Data Acquisition (SCADA) systems,
maneuvers that involve the motor inrush followed by its sudden de-energization (due, in general, to the intervention of an automatic diagnostic function), resulting into important TRVs, are not unusual. The paper aims at investigating the TRVs due to this specific type of
VCB switching by means of a model implemented in the EMTP-RV simulation environment. By making reference to a real plant, the validation of the implemented models is obtained by comparing the simulation results with some experimental transients provided by the plant data fault recorder. The paper finally discusses the adequacy of different countermeasures by analyzing their effectiveness for the TRVs limitation.
Authors: A. Borghetti, F. Napolitano, C.A. Nucci, M. Paolone, M. Sultan, N. Tripaldi
CIGRE - International Symposium “Assessing and Improving Power System Security, Reliability and Performance in Light of Changing Energy Sources” Recife, Pernambuco, Brazil, April 3-6, 2011
Topic 3 – System technical performance
Subtopic 3.5 – Switching and lightning transient on power systems. Impact on performance and measurements
Description:
The paper presents a fault location procedure for distribution networks based on the wavelet analysis of the fault-generated traveling waves. In particular, the proposed procedure implements the conti... see morenuous wavelet analysis applied to the voltage waveforms recorded during the fault in correspondence of a network bus. In order to improve the wavelet analysis, an algorithm is proposed to build specific mother wavelets inferred from the fault-originated transient waveforms. The performance of the proposed algorithm are analyzed for the case of the IEEE 34-bus test distribution network and compared with those achieved by using the more traditional Morlet mother wavelet.
Authors: Alberto Borghetti, Senior Member, IEEE, Mauro Bosetti, Mauro Di Silvestro, Carlo Alberto Nucci, Fellow, IEEE, and Mario Paolone, Member, IEEE
IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 23, NO. 2, MAY 2008
Description:
Due to the necessity of developing analysis tools in the integrated ICT and power system domain, this paper describes and compares the architecture and configuration of two different ITC-power system ... see moreco-simulation approaches called SITL (System in the Loop) and HLA (High Level Architecture) Co-simulation platforms. Both platforms make use of the communication network simulator OPNET (Optimum Network Performance). As indicated by the names, the former operates in real time, in order to perform SITL simulations, whilst the latter is based on the HLA interface between OPNET and the power network simulation environment EMTP-rv (Electromagnetic Transient Program). We provide several details on their implementation and present their features by means of the results obtained for two test cases. The paper aims at clarifying the type of analysis that can be effectively carried out by using the two different platforms.
Description:
The proposed AVR sub-circuit models consist of a few IEEE 421 standard exciter[1] and Power Systems Stabilizer and governor. Don't forget to click the require observed signals in the SM device, see O... see morebserve and Mechanical Tabs (vd, vq, if, Pmss, Efss, Omega_1, etc.) In this file, many duos and trios combinations of:
Exciter:
- IEEEX1 (dc1),
- IEEEX2,
- IEEEX4,
- IEEET5,
- EXST1,
- EXST1A,
Stabilizer:
- PSS1A,
- PSS2B,
- PSS4B,
- Q type II (var control)
Governor:
- IEEEG0,
- IEEEG1,
- IEEEG3,
- DEGOV1
- GAST,
- TGOV1,
- TGOV5[1]
IEEE Std 421.5, Recommended Practice for Excitation System Models For Power System Stability Studies, 2005
Description:
Authors:
A. Xémard, P. Baraton, B. Bressac, N. Qako, J. Mahseredjian, G. Simard, J. Ribeiro, R. Tarafi, A. Zeddam.
Abstract:
LIPS (Lightning Impact on Power Systems) is a toolbo... see morex based on EMTP (DCG version) and devoted to the calculation of the failure rate of apparatus due to lightning. This software covers direct and induced lightning. It has been developed in a partnership project between France Telecom, Hydro-Québec and électricité de France. The induced lightning nearby the electrical system. It is based on the following computational steps:
1) For each overhead line and underground cable of the electrical system, two equivalent current sources are calculated in the frequency domain, representing the illumination of the conductors by external electrical field due to lightning. These sources are evaluated in the frequency domain, taking into account the variation of the parameters of lines and cables with frequency. The conductivity of the ground is taken as finite. The modal theory is applied in the case of multi-conductor cable or line.
2) The equivalent sources are converted into time-domain and then included in an EMTP representation of the system allowing a time-domain transient computation. this approach and follow by comparisons between induced overvoltages calculated by LIPS and results from the literature.
Tag(s):
Author: AdminEMTP-RV Type: Downloaded: 163 times Date: 2012-06-18
Description:
Simulation case of the self-excitation of induction motors during startup on a series compensated radial line.
This case reproduces the results published in the book of Anderson and Farmer ... see moreentitled 'Series Compensation of Power Systems', PBLSH publisher, 1996.
Although approximate data are used, results compare surprisingly well with the figures in chapter 7.
Description:
Example of single phase Thyristor Controlled reactor using TACS control devices. This circuit reproduces the TCR case presented in the EMTP Workbook volume 4 chapter 6.
Example of single ph... see morease Thyristor Controlled reactor using TACS control devices. This circuit reproduces the TCR case presented in the EMTP Workbook volume 4 chapter 6.
The basic static Var system consists of a static switch in series with an inductor. This is normally called a phase controlled reactor, or Thyristor Controlled Reactor (TCR). The TCR is in parallel with a fixed capacitor. Together they interface with the power system at some interconnection point. The control circuit of the TCR can be divided into three parts. There is the gate pulse generator (GPG), the heart of the control system, a voltage regulator and an interface to the power systems which could be simply a RMS voltage meter.
The purpose of the gate pulse generator is to provide firing pulses to the thyristors. The regulator calculates the conduction angle, ?, which is passed to the gate pulse generator as a control signal. It is the function of the gate pulse generator to generate the correct firing pulses to achieve the requested conduction angle, ?. In this example the gate pulse generator is modeled using TACS control devices.
