Engineering tool
Transformer Winding Design Workbench
Engineering calculations for transformer windings: line and phase quantities, turns and taps, conductor area, layer and foil winding geometry (circular or racetrack), conductor length, weight, DC resistance and DC I²R loss — every result with its formula, its source (input, calculated, estimated, override) and an independent check.
Free engineering tool by Chenfan Electric. No registration. Calculated in your browser.
- 01
Transformer rating
Power, voltages and connections — phase values, currents and ratios follow.
- 02
Conductor and turns
Volts per turn, turns (and taps), current density, optional actual conductor.
- 03
Results and engineering check
Formulas, independent validation, PASS / FAIL / NOT CHECKED.
Import from Core Calculator
INCOMPLETE — No usable calculation results are available yet.
Numbers: use no thousands separators. Use a dot or an unambiguous decimal comma (0.4 or 0,4); 1,000 is rejected as ambiguous. A dot always means a decimal point, in every language.
This language is not translated yet. The workbench uses English; units, parsing and calculations are unchanged.
Transformer Rating
Override calculated phase values (Advanced)
Only for special connections. The calculated value stays visible; the entered value is marked ⚠ and the line/phase check becomes WARNING.
HV winding
LV winding
Turns & Conductor
Core data (optional)
HV winding
LV winding
Winding Geometry
Concentric windings, LV next to the core, HV outside.
HV winding
Finished geometry (end, inner, outer insulation)
Known length, weight, resistance (with basis)
Lead and manufacturing extra length
LV winding
Finished geometry (end, inner, outer insulation)
Known length, weight, resistance (with basis)
Lead and manufacturing extra length
Core and window
Needed for the window fit check. Circular windings: core circle diameter; racetrack windings: core section width and length.
Window fit is modelled for three-phase, three-limb cores only.
Clearances for the geometry fit check
Your design clearances. There is no default: a missing clearance leaves the check NOT CHECKED.
Resistance temperature and material
Load loss (optional)
Optional. The DC I²R loss is always calculated; these inputs only add an estimate or a difference.
Design / measured load loss with its basis
Results
Engineering Check
Three kinds of check are kept apart: calculation self-checks, comparisons with the conditions you entered, and items the tool does not assess. A check without the inputs it needs is NOT CHECKED — never PASS.
What the workbench calculates — and what it does not
Calculates: line/phase voltage and current, voltage ratio, turns, taps (theoretical and your turns, actual voltage, deviation, active conductor path), actual V/turn, flux density, conductor area and current density, layer / foil geometry for circular, racetrack and rounded-rectangle windings layer by layer, active and finished dimensions, conductor body / lead / manufacturing length, bare conductor weight, DC resistance at 20 °C and T, DC I²R loss, comparison with your known length, weight, resistance and load loss (same basis only), geometry fit in the window at your clearances.
Not modelled: leakage reactance; eddy, circulating, stray and structural losses; temperature rise and hot spot; impulse distribution; short-circuit forces; insulation coordination; automatic final design; complete winding pack-up; drawing recognition; disc, helical and CTC windings; half-duct arrangements; non-standard mandrels; bridge-connected active tap paths; leads with a different conductor cross-section; or conductor and winding-type recommendations.
Inputs are calculated and saved only in this browser. They are not sent to Chenfan or analytics services. Clear saved inputs on a shared device.