Three phase power cable temperature

QuickField simulation example

The three phase power cable with sector shaped conductors is surrounded by air.

Problem Type
Plane-parallel multiphysics problem of AC Magnetics coupled to Heat transfer.

Geometry

Given
Each phase conductor carries AC current I = 150 A (r.m.s.), frequency 60 Hz.
Ambient air temperature +20°C, convection coefficient 5 W/m²*K.
Thermal conductivities: aluminum 237 W/K-m, shield 380 W/K-m, insulation 0.2 W/K-m, filler 0.05 W/K-m, jacket 0.29 W/K-m.
Electrical conductivity of the aluminum conductor and copper shield depends on the temperature.

Task
Calculate the Joule heat losses per 1 meter of cable length and the conductors temperature.

Solution

1. First we make a guess about the conductors' temperature to determine their conductivity.
2. Then we simulate AC magnetics problem and calculate losses in all conductors, including the shield and 0-conductor.
3. Then we transfer the Joule heat losses to a heat transfer problem to calculate temperature.

Results
Joule heat loss in the conductor is 6.3 Watts per 1 meter of conductor length. Joule heat loss in the shield is 0.4 W/m.
Conductor temperature is 54°C, cable surface temperature is 48°C.

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