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Power system analysis, control and protection are all based on accurately frequency phasor measurements due to their explicit physical meaning and concise mathematical presentation. Rapidly development of power networks and widely uses of power electronic devices result in complicated transient during faults and disturbances in modern power systems. Some Prony-based methods, such as the matrix pencil...
Distributed Generation (DG) influences the traditional protection schemes. In this paper the influence of DG on the protections of the Belgian grid operator, Elia, is explained for a 70 kV/15 kV transformer in antenna. Based on the method of the symmetrical components, the detection of two different types of protections, zero-sequence overvoltage, U0>, and negative-sequence overvoltage, U2>,...
This paper presents performance of two charging current compensation methods used in commercially available differential relays. This paper appreciates importance of cable models on protection and settings application studies and on estimation of performance of charging current compensation methods. The problem is split in to a) Significance of Power Cable Modelling and b) Protection performance evaluations...
A laboratory based demonstrator has been constructed to study the Active Impedance Estimation (AIE) technique as a means of locating faults on a power system. The demonstrator has been used to verify results from simulation experimentally. The AIE system and associated signal processing are presented and some of the issues that have been encountered are discussed. The presented simulation and experimental...
In such new distribution grid structures, protection schemes employed in mature grid have started to change caused by the unpredictable nature of renewable generation units. Thus, the protection devices and relevant control methodologies should dynamically be adapted to changing power flow and fault conditions within the grid system. The protection issue in smart distribution grids with additional...
It is well known that series arc faults in Low Voltage DC (LVDC) distribution system occur at unintended points of discontinuity within an electrical circuit. These faults can make circuit breakers not respond timely due to low fault current. It, therefore, is needed to detect the series fault properly for protecting circuits from electrical fires. This paper presents a scheme to detect the series...
The application of IEEE1588 in time synchronizing system of smart distribution grid is researched in this paper. Topologic structure of communication system of distribution grid is analysed in the second instance. Redundancy configuration and auto-select technique of precise clock source are brought forward afterwards. Thirdly, clock mode selection scheme of backbone layer, access layer and distribution...
A novel double-ended algorithm devoted to series arc fault location is presented. It utilizes the current and voltage transient during arc fault initiation for the fault distance estimation. Experimental results have demonstrated that this method can provide an accurate series arc fault location within a short time.
The paper describes the design and implementation of a new protection system consisting of a permissive overreach (PO) pilot relaying scheme with directional overcurrent relays for both phase and ground faults supporting closed-loop operation in MV network; attention is focused on ground fault relaying of loop networks operated with ungrounded or compensated neutral. Relevant zero-sequence quantities...
This paper describes the current progress of the project developing a satellite based Loss-of-Mains (LOM) protection based on accumulated voltage phase angle difference (VPAD). In the initial stage of the laboratory trial, relay prototype in Opal-RT/RT-lab, test network modelled in RTDS/RSCAD and a commercial SEL-PMU are interconnected to establish a hardware-in-the-loop test platform. With a series...
Microgrid is a low-voltage network with distribution generation which can be operated in parallel to the utility grid or in an islanded condition. The protection of microgrid faces a real challenge due to its changable operating conditions. Under islanded mode, large fault current in-feed from the network is no longer available. In addition, most of the renewable energy sources are connected to the...
Since IEC 61850 became the widely used standard for substation communication with a lot of implementations testing is an important issue. Edition 2 is available since 2012 and offers a wide range of possibilities and sophisticated details. Due to the huge amount of prospects and different places where testing can be located and marked systematization might be helpful and will presented as an introduction...
In addition to the anticipated gradual reduction of system inertia in the future, its variability due to more flexible system control and management over time will also be an issue in future power system operation. This paper focuses on the impact of inertia reduction and variation on existing frequency-based protection during loss of large infeed contingency, with the UK power system used as a basis...
Back flashover faults resulting from lightning strokes hitting the shield wire(s) or tower(s) are one of the major causes of power interruptions on the double-circuit 69/138 kV overhead transmission lines in Jamaica. Computational analysis with the aid of Alternative Transient Program-Electromagnetic Transient Program (ATP-EMTP) simulations was performed on a section of the affected lines to identify...
A waste recycling and generation plant experienced significant power and frequency fluctuations following a steam valve closure on the generators prime mover. The reverse power protection did not remove the electrical machine from the network as quickly as expected, and concerns were raised regarding the resulting damage potential. This paper presents the modelling of the system and the improved reverse...
Optimal power flow (OPF) simulations are used to study the effects of large-scale renewable energy installations implemented on an autonomous power system. The economic effects are analyzed under several different conditions and operating scenarios. Crete's power system with ultra high level of RES penetration is simulated and investigated using commercial software. The total fuel and emissions costs,...
For smart grid development, one of the key expectations is that the data should be accessible to and readily interpreted by different applications. Presently, protection settings are represented using proprietary parameters and stored in various file formats. This makes it very difficult for computer applications to manipulate such data directly. This paper introduces a process that translates the...
There are two common methods applied in the traction line fault location, the travelling wave method and the impedance method. Each method has advantages and disadvantages. It is difficult to achieve optimized goal with only one method. Therefore, this paper combines the two algorithms to improve the accuracy of fault location. MATLAB/Simulink software was used to test and validate the proposed fault...
Rte has been using Real-Time Simulation for the functional qualification of protections for many years. The recent commissioning of a new real-time simulator implied a migration of the existing test templates to the new environment and a validation of the new models. This paper explains the strategy applied for the validation, describes the issues of this migration- and validation process and gives...
To deliver the increasing capacity and reliability of train services which railways must deliver, the electrification fixed system must itself be highly reliable and available. Main line railways demand high power transmission and traction system energy demand will continue to grow. There remains however the need to contain and reduce first and whole life cost. This paper sets out how IEC 61850 can...
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