Enter Base Values

Formulas

Zpu,new = Zpu,old × (MVAnew ÷ MVAold) × (kVold ÷ kVnew)2

Zbase = kVLL2 ÷ MVA

Ibase = MVA × 1000 ÷ (√3 × kVLL)

Example

An impedance of 0.10 pu on a 50 MVA, 13.8 kV base becomes 0.20 pu on a 100 MVA, 13.8 kV base.

Assumptions

The MVA values are total three-phase bases and voltage is line-to-line. Base voltages on opposite sides of a transformer should follow the transformer ratio.

A base conversion changes the numerical per-unit value, not the physical impedance.

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