Calculate voltage regulation between no-load and full-load conditions.
Regulation is the voltage droop between no load and full load. It can be computed from measured voltages or predicted from the transformer’s percentage impedance and the load power factor, and the two should agree closely. Reactance dominates regulation at poor power factor, which is why a lagging load causes far more voltage droop than a unity-power-factor one of the same kW.
Transformer Regulation
Regulation % = (V_noload − V_fullload) ÷ V_fullload × 100 ≈ %R cos φ + %X sin φ
Regulation % = (V_noload − V_fullload) ÷ V_fullload × 100 ≈ %R cos φ + %X sin φ Regulation is the voltage droop between no load and full load. It can be computed from measured voltages or predicted from the transformer’s percentage impedance and the load power factor, and the two should agree closely.
Reactance dominates regulation at poor power factor, which is why a lagging load causes far more voltage droop than a unity-power-factor one of the same kW.
This calculator takes 5 inputs: No-load secondary voltage, Full-load secondary voltage, Percentage resistance, Percentage reactance, Load power factor. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.