Results 161 to 170 of about 99,550 (205)

Operation Logic Proposed for Time Overcurrent Relays

IEEE Transactions on Power Delivery, 2006
This paper presents a new logic of operation for time overcurrent relays. With the application of the proposed technique, the sensitivity of time overcurrent relays is increased. In order to obtain this, the relay operates with a dynamic pickup setting, such as load current. Additionally, fast operation of overcurrent relays is obtained. The functional
A. Conde, E. Vazquez
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Directional overcurrent relays

2011
Directional overcurrent protection is used when it is necessary to protect the system against fault currents that could circulate in both directions through a system element, and when bidirectional overcurrent protection could produce unnecessary disconnection of circuits.
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Testing dynamic characteristics of overcurrent relays

IEEE WESCANEX 93 Communications, Computers and Power in the Modern Environment - Conference Proceedings, 2002
Test methods for determining the dynamic characteristics of an overcurrent relay are discussed. By dynamics is meant the response of the relay to a current of varying magnitude. The test method, originated by IREQ, is used by Hydro Quebec to determine the ability of new relays to coordinate with the installed base of induction relays.
G. Benmouyal, S.E. Zocholl
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Design and Implementation of Overcurrent Protection Relay

Journal of Electrical Engineering & Technology, 2020
Protective relays have been designed with different technologies resulting in electromechanical, solid-state, and numerical devices. Speed and reliability are the two most important characteristics of a protective relay. Other capabilities such as monitoring and recording are supposed to be of secondary priority. The new technology using combination of
Mohammed Y. Suliman, Mohammed Ghazal
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ANN based directional overcurrent relay

2001 IEEE/PES Transmission and Distribution Conference and Exposition. Developing New Perspectives (Cat. No.01CH37294), 2002
This paper describes the design and development of an ANN based novel directional overcurrent relay. A multi-layer feedforward neural network (FFNN) trained with the error backpropagation algorithm has been developed to realize this relay. The ANN based algorithm is off line tested using different simulation equations for overcurrent and voltage under ...
D.N. Vishwakarma, Z. Moravej
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Current-Only Directional Overcurrent Relay

IEEE Sensors Journal, 2011
Overcurrent relays are widely used for protection of power systems, directional ones for transmission side, and nondirectional ones for distribution side. The fault direction may be forward (between relay and grid), or reverse (between relay and source), the normal power flow being from source to the grid. Known directional overcurrent relays rely on a
Abhisek Ukil, Bernhard Deck, Vishal H. Shah   +2 more
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A new one-cycle directional overcurrent relay

Electrical Engineering, 1943
This paper describes a new one-cycle directional overcurrent relay which is not limited in its application by lack of contact co-ordination. That contact coordination is important is indicated by the many incorrect relay operations which have been traced to the common practice of adding instantaneous attachment to directional overcurrent relays.
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Time-Overcurrent Relay Coordination: A Review

International Journal of Emerging Electric Power Systems, 2005
When two protective apparatus installed in series have characteristics, which provide a specified operating sequence, they are said to be coordinated or selective. The coordination of directional overcurrent relays poses serious problems in the modern complex power system networks, which are interconnected.
Dinesh Birla, Rudra Prakash Maheshwari, Hari Om Gupta   +2 more
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A novel overcurrent relay with universal characteristics

2001 IEEE/PES Transmission and Distribution Conference and Exposition. Developing New Perspectives (Cat. No.01CH37294), 2002
In this paper, a novel overcurrent relay with universal characteristics is proposed. The relay can be uniquely coordinated with electromechanical, static and other numerical relay versions in a flexible pattern. Two electromechanical relays are experimentally tested and the curves are efficiently modeled.
H.A. Darwish, A.I. Taalab, H. Assal
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Overcurrent relay coordination by evolutionary programming

Electric Power Systems Research, 2000
Abstract This paper presents a novel optimization technique based on evolutionary programming for overcurrent (OC) relay coordination in ring fed distribution networks. Since the problem has multi-optimum points, ordinary mathematical based optimization techniques will fail.
C.W. So, K.K. Li
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