QuickField

A new approach to field modelling

Main >> Applications >> Sample problems >> Line-to-line short circuit

Phase to phase fault

QuickField simulation example

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
Transmission line pole Tangent tower design, 110kV A B C Soil 2 m 3.5 m 2 m 3 m 14.5 m 3 m

Aluminum Conductor Steel Reinforced (ACSR):
Aluminum Conductor Steel Reinforced (ACSR) ACSR conductor for HV transmission line Steel Aluminum

Line-to-line short circuit:
Line-to-line short circuit Line-to-line short circuit electric scheme Rload = 100 Ohm Lload = 0.23 H Electrical network, 20 km S 110 kV A B C

Given
Rated voltage (RMS) Urated = 110 kV;
Rated current (RMS) Irated = 440 A;
Line length L = 20 km;
Loading parameters Rload = 100 Ohm; Lload = 0.23 H.

Task
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 electrical conductivity which varies in time:
σ(t) = 0.01 + 56e6 * STEP(t - 1).
Short-circuit bridge is a QuickField block

Results
Electromagnetic force of interaction between phases A and B is fA-B = 2.6 N/m.
transmission line short-circuit currents

Maximal short-circuit current Imax = 8 kA.