Phase to phase fault

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:

Watch online on YouTube.

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