QuickField

A new approach to field modelling

Main >> Applications >> Sample problems >> Electric arc furnace transformer

Electric arc furnace transformer short circuit

QuickField simulation example

Short circuit experiment refers to the standard test of transformers. In the short-circuit mode the secondary winding leads are short-connected and the voltage source is adjusted to provide the rated current in the primary winding.

Problem Type
Plane-parallel problem of AC Magnetics.

Geometry
Core depth Lz = 292 mm.
Core Phase A Phase B Phase C А+ А- B+ B- C+ C- -a +a -b +b -c +c 292 mm 1424 mm 1226 mm

Initial data:
Rated voltage of the primary winding U = 6 kV;
Rated current of the primary winding I = 25 A;
Frequency f = 50 Hz;
Winding connection scheme Δ-Δ

Task
Estimate the transformer short circuit voltage, axial forces in the windings, build the stray fluxes field picture.

Solution
The winding connection scheme is formed with the help of a connected electrical circuit.
Current source of rated magnitude is connected to the primary winding. Measured voltage drop on the source shows the short circuit voltage.

Results
Short circuit voltage is 377 V, which is 377/6000 = 6% of the rated voltage value.

Stray fluxes in the electric arc furnace transformer:
Stray flux field in windings

Axial force acting on the end coil of high-voltage winding is 18 N.