Results 171 to 180 of about 6,262 (228)

Modeling overcurrent relay characteristics

IEEE Computer Applications in Power, 1992
An approach to computer modeling of the time-current characteristics of protective devices that relies on interactive manipulation and fitting of the curves, which are modeled mathematically as splines is presented. The approach is much easier to use than the commonly used curve-fitting methods, which are reviewed, and it does not require a digitizer ...
S. Chan, R. Maurer
openaire   +1 more source

The Universal Overcurrent Relay

IEEE Industry Applications Magazine, 1996
A comprehensive list of nondirectional overcurrent relays would include thermal overload, inverse-time, definite time, and instantaneous relays. The list could be further classified by operating quantities including individual phase, residual, and negative-sequence current.
E. O. Schweitzer, S. E. Zocholl
openaire   +1 more source

Microcontroller based overcurrent relay and directional overcurrent relay with ground fault protection

Electric Power Systems Research, 1996
Abstract This paper presents the design and construction of overcurrent and directional overcurrent relays with ground fault protection for the protection of three-phase subtransmission and distribution systems, using a 16-bit microprocessor, the Intel 8096BH. The relay obtains the system currents at the rate of 12 samples per cycle and estimates the
Zhijun, G., Elangovan, S., Liew, A.C.
openaire   +1 more source

Microprocessor-Based Overcurrent Relays

IEEE Transactions on Industrial Electronics, 1986
Inverse overcurrent is normally associated with the overcurrent relay types, the operation time is inversely proportional (in certain degrees) with their overcurrent ratio.
Mudhafar A. Al-Nema, Sinan M. Bashi, Abdulhadi A. Ubaid   +2 more
openaire   +1 more source

Directional Overcurrent Relaying (67) Concepts

59th Annual Conference for Protective Relay Engineers, 2006., 2006
Directional overcurrent relaying (67) refers to relaying that can use the phase relationship of voltage and current to determine direction to a fault. There are a variety of concepts by which this task is done. This paper will review the mainstream methods by which 67 type directional decisions are made by protective relays.
J. Horak, W. Babic
openaire   +2 more sources

A Field-Programmable Time-Overcurrent Relay

IEEE Power Engineering Review, 1986
This paper presents the underlying principles and the test results for a microprocessor based time overcurrent relay. The main feature is the use of a portable pocket computer with an RS-232C communication link for the man machine interface. The calculator serves to enter and modify the set vatues pick up current, instantaneous characteristics.
Gabriel Bienmouval, Sylvain Boismenu
openaire   +1 more source

Optimal Combined Overcurrent and Distance Relays Coordination Incorporating Intelligent Overcurrent Relays Characteristic Selection

IEEE Transactions on Power Delivery, 2011
In this paper, a new objective function (OF) within the genetic algorithm (GA) approach is presented to solve the optimization problem of coordination of overcurrent and distance relays. The existing objective function of overcurrent (O/C) relays coordination is improved and extended to include the coordination of O/C and distance relays.
Reza Mohammadi Chabanloo, Hossein Askarian Abyaneh, Somayeh Sadat Hashemi Kamangar, Farzad Razavi   +3 more
openaire   +1 more source

Microcomputer-based multiple overcurrent relays

Computers in Industry, 1993
Abstract This paper presents an application of the most recent modern technology to implement overcurrent relaying functions in a power system. A microprocessor-based single and multiple overcurrent relays have been reported. In this work it is shown that a microcomputer in conjunction with an interface board can be economically used to develop a ...
Faisal Fadul, Monir Ahmad
openaire   +1 more source

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
openaire   +1 more source

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
openaire   +1 more source