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Transmission line electromagnetic compatibility (EMC)

QuickField simulation example

Two three phase transmission lines go side by side for 10 km. Each transmission line is formed by 3 parallel copper conductors 1 cm diameter each. Conductors are placed on the same height above the ground (flat formation). Conductors are separated by 1 m air clearance. Distance between the nearest conductors of two transmission lines is 18 meters. Left transmission line is energized by three phase currents system.

Problem Type
Plane-parallel problem of AC magnetics.

Geometry
Transmission line electromagnetic compatibility Two 3-wire transmission lines are placed at 10 m above the ground. A B C ≋ 250 A, 50 Hz A B C Soil 18 m 10 m

Given
Left line phase electric current: 250 A (r.m.s.)
Frequency: 50 Hz
Copper electrical conductivity 60 MS/m
Soil electrical conductivity: 0.02 S/m
Transmission line length: 10 km

Task
Find the induced voltages in the right transmission line per 10 km of its length.

Solution
In QuickField we should specify peak values of electric current, that is √2 times the root mean square (r.m.s.) value: 250*√2 = 353 А

Results
Measured end-to-end voltages for second transmission line conductors
VA = 22.3 V
VB = 21.0 V
VC = 19.8 V

Current density distribution in the soil and induced voltages in secondary transmission line conductors.
transmission line emc