60 research outputs found
Application of ANN and Genetic Algorithm for Evaluation the Optimum Location of Arresters on Power Networks due to the Switching Overvoltages
Switching surges are of primary importance in insulation co-ordination of EHV lines, as well as in
designing insulation of apparatuses. The magnitude and shape of the switching overvoltages vary with
the system parameters, network configuration and the point-on-wave where the switching operation
takes place. This paper presents an artificial neural network (ANN) based approach to estimate the
peak value of overvoltages and the global risk of failure generated by switching transients during line
energizing or re-energizing in different nodes of a power network. Then a genetic algorithm (GA)
based method is developed to find the best position of surge arresters on power networks so as to
minimize the global risk of the network
Derivation of Theoretical Formulas of the Frequency Component Contained in the Overvoltage Related to Long EHV Cables
Experimental and theoretical analysis of cable discharge
This paper focuses on the phenomenon of discharge of HVAC cables, which is a concern for utilities when performing AC/DC tests, during maintenance works, and more recently when switching cables for grid voltage control. The study is based on field and laboratory tests of 275 kV pressurized-oil-filled (POF) cables, analytical calculations, and simulations. The contributions of this paper are: field and laboratory measurements of voltages and leakage currents during cable discharge, including a field test carried out in 2015 by the National Grid (UK) on a 275 kV POF cable of 21 km; a method for estimating the leakage resistance and the time required to discharge a cable system using simple parallel RC circuit theory; and typical values of leakage resistance, leakage current, and discharge time for 275 kV cable systems. The influence of temperature, electric field, and humidity on cable discharge is also discussed and a correction factor to account for the impact of humidity is proposed
Derivation of an earth-return impedance of an overhead multi-conductor considering displacement currents
An Investigation of Induced Voltages to an Underground Gas Pipeline from an Overhead Transmission Line
Cable system transients: theory, modeling and simulation
A systematic and comprehensive introduction to electromagnetic transient in cable systems, written by the internationally renowned pioneer in this field Presents a systematic and comprehensive introduction to electromagnetic transient in cable systems Written by the internationally renowned pioneer in the field Thorough coverage of the state of the art on the topic, presented in a well-organized, logical style, from fundamentals and practical applications A companion website is availabl
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