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Summary form only given. A full-order, voltage-behind-reactance synchronous machine model has recently been proposed in the literature. This paper extends the voltage-behind-reactance formulation for the EMTP-type solution, in which the rotor subsystem is expressed in q-d coordinates and the stator subsystem is expressed in abc phase coordinates. The model interface with the nodal-analysis network...
Summary form only given. In this paper, experimental and analytical studies of the electromagnetic transient response of a buried bare wire and a ground grid are presented. The electromagnetic transient response of a ground grid has effects on induced surges in low-voltage and control circuits of power stations, substations and telecommunication stations. Therefore, the experimental and theoretical...
Transient overvoltages encountered by the power system equipment are mainly divided into three types: lightning surges, switch surges, and power frequency overvoltages. This paper presents a transient overvoltage study in a 345 kV hybrid overhead and underground transmission system that serves a high-tech industrial park. Based on the actual system information, the distributed parameter model is adopted...
The relaying signals by the use of EMT-type programs have demonstrated excellent results, but a quantity of requirements must be taken into account to be considered as realistic inputs for protection relays. This paper is a basic discussion of the factors to be considered when modeling power systems and protection relays for the purpose of developing or testing protection algorithms. Models of transmission...
This paper presents an overview on available tools for the simulation of electromagnetic transients in power systems. Simulation tools range from specialized computer programs operating in real-time or non-real-time modes, to customized general purpose modeling environments. The various categories of tools are presented with highlights on applicability ranges and available modeling capabilities.
Grid interface of renewable energy based distributed generation requires satisfying the interconnection requirements stipulated by the local distribution utility. Detailed testing of protection and control systems is required to ensure conformity to wide ranging interconnection requirements such as fault ride through capability, protection against islanding, harmonics and voltage flicker limits. Electromagnetic...
High impedance faults (HIFs) are difficult to detect by overcurrent protection relays. This paper presents an ATP/EMTP fault simulations studies based algorithm for high impedance fault detection in extra high voltage transmission line. The scheme recognizes the distortion of the voltage waveforms caused by the arcs usually associated with HIF. The discrete wavelet transform (DWT) based analysis,...
This paper presents an overview on the currently applied computational methods for the simulation and analysis of electromagnetic transients in power systems. The paper starts by reviewing the fundamental modeling concepts and applicability ranges and follows by focusing on some particular numerical issues and problems. Ongoing research topics are also discussed.
As NASA readies itself for new space exploration initiatives starting with a human return to the Moon by the year 2020 eventually leading to human exploration of Mars, the requirements for a safe and reliable power system will become important issues. A preliminary study of a proposed hybrid AC/DC distribution system with a power electronic interface is investigated. A static synchronous compensator...
Recent wavelet developments in power engineering applications, include detection, localization, classification, identification, storage, compression, and network/system analysis of the power quality disturbance signals, to very recently, power system relaying [1,2,3,4]. This paper assesses the online use of wavelet analysis to power system relaying. The paper presents a novel technique for transmission-line...
In this paper, features of earth faults due to leaning trees are extracted from the network phase currents using the discrete wavelet transform (DWT). Due to the associated arc reignitions, the initial transients in the electrical network give behavioral traits. The detection security is also enhanced because the DWT is responded to a periodicity of the initial transients. The absolute sum of the...
Adding capacitors to an electric power system provides well known benefits, including power factor correction, voltage support and increase of active power transfer capacity. However, the capacitor banks modify the harmonic voltages and currents in the network and give rise to current and voltage transients, stressing switching devices and sensitive loads. The first part of the paper describes measurements...
This paper presents a new method for locating faults on three-terminal power lines. Estimation of a distance to fault and indication of a faulted section is performed using three- phase current from all three terminals and additionally three- phase voltage from the terminal at which a fault locator is installed. The fault location algorithm consists of three subroutines designated for locating faults...
Transformer windings might be shifted because of short-circuit current, aging or impact during transportation. The shift modifies the dielectric space between the layers of the windings and may cause an insulation breakdown. Since transformers are expensive to replace, it is vital that their condition are determined accurately without having to dismantle the apparatus to inspect it visually. Generally,...
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