transmission line FEA simulation, short circuit current magnetic field

Phase to phase fault is one of the most widespread damages of the transmission lines in electrical networks (15-20 % from total number of failures). This model shows how to simulate the phase to phase fault in QuickField.

Tangent tower design. All dimensions are in meters.

Wire design

Line-to-line short circuit

Given: Rated voltage (RMS) U_{rated} = 110 kV;
Rated current (RMS) I_{rated} = 440 A;
Line length l = 20 km;
Loading parameters R_{load} = 100 Ohm;
L_{load} = 0.23 H.

Problem: Determine the transient process currents after a short circuit occurred. Find the electromagnetic forces acting on the lines during this process.

Solution: To solve this problem it is necessary to simulate both field part and circuit part. The scheme of connection of power supply phase windings, loading, elements of the circuit and short-circuit bridge is presented in the circuit model, created by the QuickField Circuit Editor.

Short-circuit bridge is a QuickField block with the resistance which varies in time. This dependence is implemented using the electrical conductivity as a function of the temperature, which is also function of time - as σ(T(t)) function.

Results: Short-circuit current (amplitude) I_{max} = 7000 A.
Electromagnetic force of interaction between phases A and BF_{A-B} = 1780 N/km.