Transmission Line, Railroad and Pipeline Common Corridor Study

Low-frequency magnetic fields from electrical appliances and power lines

“…From Parker, the mutual impedance between two parallel cables located in positions and and parallel to the axis is (1) where and , , and are the conductivity, the permittivity, and the permeability of the earth, respectively, and the angular frequency.…”

“…In recent years, with the purpose of improving services, "corridors" have been proposed that include common services for energy distribution, data transmission lines, gas conduits, etc. Given that the energy is transported by the electromagnetic field that is propagated throughout the line, undesired effects can be produced on the other services [1], since the high-intensity electromagnetic fields can induce important voltages and currents in conducting elements located in their proximity (fences, pipelines, telephone lines, other transmission lines, etc. ).…”

Συμβολή Στον Υπολογισμό Της Επαγωγικής Επίδρασης Γραμμών Μεταφοράς Ηλεκτρικής Ενέργειας Σε Υπόγειους Μεταλλικούς Αγωγούς

“…Η µέθοδος αυτή, που εφαρµόστηκε στην έρηµο Mojave της California, είναι γενικά πολύ χρήσιµη σε περιπτώσεις που το έδαφος έχει µεγάλη ειδική αντίσταση και συνεπώς η συµβατική µέθοδος γείωσης του σωλήνα είναι ιδιαίτερα δύσκολη. Με περαιτέρω χρηµατοδότηση από την EPRI και την εταιρία ηλεκτρικών σιδηροδρόµων των ΗΠΑ, ο Frazier ασχολήθηκε και µε τις επιδράσεις σε κανονική λειτουργία σε υπόγειους σωλήνες και γραµµές ηλεκτροδότησης σιδηροδρόµων [25,26], κατασκευάζοντας ένα πρόγραµµα µε ονοµασία CORRIDOR.…”

“…A technical recommendation was developed in Germany based on these studies, which was revised later [18], by utilizing more advanced and sophisticated analytical models in a computer program. During the late 70's and early 80's, two research projects of the Electrical Power Research Institute (EPRI) and the American Gas Association (AGA) introduced practical analytical expressions that could be programmed on hand held calculators [19][20][21][22][23] and computerized techniques [24][25][26]. In the following years, EPRI and AGA joined forces and developed a computer program [27][28][29], which utilizes equivalent circuits with concentrated or distributed elements, with the self and mutual inductances being calculated using classic formulae from Carson [11], Pollaczek [12], Sunde [17] and Wait [31].…”