Electrical Efficiency
Transformer Losses and Efficiency Analysis
Transformers incur no-load and load-dependent losses while transferring energy between voltage levels. Nameplate efficiency alone is insufficient; actual cost depends on the facility's interval load profile, energy price, temperature and operating hours.
No-load and load losses
Core loss occurs while the transformer remains energised and depends on voltage. Winding losses increase approximately with the square of current, so high-load hours can have a disproportionate effect on annual loss cost.
Calculate with the load profile
Build a transformer-loading time series from meter data and calculate interval energy loss using manufacturer loss values. Parallel-operation or replacement decisions require separate visibility into peak, average and low-load periods.
Life-cycle cost
Compare purchase price with annual loss cost, maintenance, expected life and failure risk using discounted cash flow. Depending on utilisation, the economic value of a low-loss transformer can exceed the upfront price difference.
Sources
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