Transformer Efficiency & Losses Estimator

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Electrical & Electronics Engineering — Circuits, Power Systems, Electronics Lab

Tranche

tranche-4

Evidence ID

t4-066

Ledger rows

1

No ledger note is attached.

Review findings

The honest label is appropriate, but the implementation needs an explicit full-load copper-loss reference, decimal-versus-percent load convention, output-power formula, valid input constraints, and a defined efficiency-curve sweep before the specification can pass.

Formula and scope findings

• η=Pout/(Pout+Pcu+Pfe) is standard when Pout is real output power and Pcu and Pfe are real losses in watts.
• Pcu∝(load%)² is incomplete as an executable formula: it must define a reference copper loss, normally Pcu(load)=Pcu_full_load×load_fraction².
• The specification does not state whether the copper-loss input is the full-load copper loss; this is required to calculate load-dependent copper loss.
• The specification uses load% while the input is called load fraction; the representation must be explicitly defined as either a decimal fraction from 0 to 1 or a percentage from 0 to 100.
• No explicit formula is provided for output power. Under the usual transformer model, Pout=rated_VA×load_fraction×PF.
• An efficiency curve requires a defined load sweep, domain, step size, and treatment of invalid load fractions; these are missing.

Unit assumptions

• rated_VA is apparent power in VA.
• copper_loss_full_load_W and core_loss_W are real power losses in watts.
• PF is dimensionless and lies from 0 to 1; it is assumed constant over the load curve.
• load_fraction is a decimal fraction from 0 to 1, so 25% is entered as 0.25.
• Pout=rated_VA×load_fraction×PF, producing watts because VA×PF is treated as real watts.
• Core loss Pfe is assumed constant with load and frequency, voltage, and waveform.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The zero-output, zero-loss combination produces an undefined 0/0 efficiency, and the specification does not define behavior for load fractions above 1.0 or the PF unit convention.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "rated_VA": 1000,
    "copper_loss_full_load_W": 40,
    "core_loss_W": 10,
    "PF": 0.8,
    "load_fraction": 0.5
  },
  "expected_outputs": {
    "Pout_W": 400,
    "Pcu_W": 10,
    "Pfe_W": 10,
    "total_loss_W": 20,
    "efficiency": 0.9523809523809523,
    "efficiency_percent": 95.23809523809523
  },
  "working": "Pout=1000×0.5×0.8=400 W. Pcu=40×0.5²=40×0.25=10 W. Pfe=10 W. Total loss=10+10=20 W. η=400/(400+10+10)=400/420=20/21=0.9523809523809523=95.23809523809523%."
}

Related workflows

No source-defined multi-instrument workflow membership is recorded.

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche4/tranche4-results.json
• BOUNDARY_HAZARD_CATALOG.json