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The increasing integration of distributed and renewable energy sources into the electrical power network presents challenges for the operation and management of the network. New techniques are required to ensure the effective management of the balance between supply and demand, and the proper maintenance of voltage stability and power quality in the network. A new energy management system, designed...
One of the main characteristics of Smart Grids is self healing. This means that the grid should rapidly detects, analyzes, acts and restores for system instabilities. Controlled islanding is one of the techniques used to mitigate these system instabilities. System islanding is often considered as the final stage of power system defense plans. The goal is to preserve stable areas of the faulted power...
Modern power supplies must provide reliable, high-quality power. Therefore, it is important that a transmission line fault be identified accurately, reliably and corrected as soon as possible. A method for classifying fault type based on short time Fourier transform (STFT) is provided in this paper. STFT is a means of signal processing in which a Fourier transform (FT) is performed by setting a window...
A decentralized coordinated control is researched based on multi-agent structure for transient stability improvement of large-scale power system in this paper. First, a multi-agent system (MAS) model is structured based on the wide-area measurement system (WAMS), which consists of both upper and lower level agents. The upper level coordinated agents are mainly responsible for coordinating and controlling...
A single-machine-equivalent (SIME) based emergency control (EC) scheme that incorporates synchronized measurements is described in the paper. This EC scheme resolves the transient stability problems experienced when serious disturbance occurs on critical transmission lines. The control actions are based on modifying the impedance of a thyristor controlled series compensator (TCSC). The SIME approach...
Application of local data at receiving node of the system to estimate and control its parameters were considered in the paper. Using Thevenin model some methods were developed, analysed and simulated allowing to estimate and control stability margin and voltage level. The results can be used to construct voltage controller on basis of power electronics.
Phasor Measurement Units (PMUs) have the potential to play an essential role in power system monitoring and operation in the future, particularly for power systems incorporating increasing amounts of distributed generation (DG) and possibly systems operating in islanded mode in the future [1]. Their ability to directly measure and provide the voltage and current phasors at the PMU location offers...
Autoreclosure provides a means of improving power transmitting ability and system stability. The conventional reclosure adopts the fixed dead time interval strategy, that is, the reclosure is activated after a time delay to restore the system to normal as quickly as possible without regard to the system conditions; however, these simple techniques cannot give the optimal operating performance. For...
The paper presents a new pole slipping protection method that combines high efficiency of pole slip detection and sensitivity to many sources of potential pole slipping. To simplify the setup process the adaptive settings are calculated continuously. The new adaptive method utilizes active and reactive power measurements on machine terminals to ascertain that the synchronous machine is committed to...
Decentralized Energy Resources (DER) and especially wind farms became a challenge for protection, automation and control in the grids. Transmission system operators as well as distribution system operators require tests of Loss of Mains and other decoupling protection functions. In some countries certification of these functions is required. The units are equipped with a huge amount of internal protection...
With their increasing number, it is getting important that decentralized and renewable energy sources are supporting the stabilization of the system voltage after short voltage dropouts. Often, in the past, these generators were disconnected during network faults. This is not adequate anymore, as it would lead to a loss of a considerable amount of feed-in power. However, if the generators stay connected,...
This paper presents a novel approach for the detection of abnormal power system states that force systems into blackout. K-means clustering techniques and two types of distances for identifying pattern clusters are used to detect abnormal conditions. PCA is used for the reduction of the data matrix for faster calculations. The proposed hybrid technique is then demonstrated on an IEEE 14-bus system.
Recently the importance of Wide-Area Situational Awareness (WASA) has increased as it can form the basis for power system stabilisation systems or be part of a smart grid. The standardisation of communication interfaces with the ability to integrate many kinds of sub systems becomes increasingly important in enabling the build of a standard WASA system. In Japan, Wide Area Monitoring, Protection and...
Future power systems face several challenges; one of them is the use of high power converters that decouple new energy sources from the AC power grid. This decreases the total system inertia affecting its ability to overcome system frequency's disturbances. The wind power industry has created a controller to enable inertial response on wind turbines generators: Artificial, Emulated, Simulated, or...
Distance relays used for transmission line protection can mal-operate on power swing. This paper presents protection schemes for out of step detection based on synchronized phasor measurement. Voltages and currents at both the ends of a transmission line are used to derive the parameters required for designing these schemes. The proposed schemes can distinguish stable and unstable power swing and...
This paper discusses potential extreme scenarios which could result in unstable conditions on the main interconnected electricity transmission system of Oman. Case studies on loss-of-stability scenarios between different parts of the network are examined. The objectives of the study are to identify possible locations of the electrical centre of swing and to develop an approach for controllable system...
This paper aims to present the modeling and simulation of numerical differential protection of power transformers using the software ATP/ATPDraw and its MODELS environment. In order to validate the relay model, simulations were carried out using a simplified electrical power system whose parameters were obtained from a real system. The results reveal the advantages of using this type of modeling,...
Real-time Dynamics Monitoring System(RDMS) is applicable to monitor the dynamic behaviors of large region grid, such as low-frequency oscillation, short-circuit, frequency fluctuation, etc. For the perturbation in power systems occurs incidentally, it's difficult to collect enough cases for an complete test on RDMS, which may lead to potential risks of outage. So it's necessary to study more efficient...
The increase of the electric power demand is at the level 2–3% per year, and in some regions of the world may become much higher. In the same time the infrastructure of power systems develop much slower. The smart grid technology is to use modern telecommunication and informatics to bridge the gap. The aim is to integrate generation, transmission, distribution and consumption of the electrical energy...
Distributed generation is increasingly likely to play a major role in electricity supply systems as recognition is made of its low carbon credentials. However, the integration of these units at distribution voltages is a major challenge for utilities. One particular issue is that generators may, unintentionally, continue to supply local demand when areas of the network are isolated from the main system...
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