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Phase to phase fault

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.

Problem Type:
Plane-parallel problem of transient magnetics.

Geometry:

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 B F_A-B = 1780 N/km.

Illustration of the short-circuit currents:

Download simulation files (files may be viewed using any QuickField Edition).