Transformer Impedance Calculator
Calculate transformer impedance parameters, voltage drop, and short circuit current. Essential for electrical system design, protection coordination, and fault analysis.
Step 1: Transformer Specifications
Understanding Transformer Impedance
Transformer impedance (Z%) represents the voltage drop at full load due to winding resistance and leakage reactance. Typical values range from 3-10% for distribution transformers. Higher impedance limits fault current but increases voltage drop.
Step 2: Load & Analysis
About X/R Ratio
The X/R ratio indicates the relationship between reactance (X) and resistance (R). Higher X/R ratios result in higher asymmetric fault currents and slower DC offset decay. Typical values range from 3-15 for distribution transformers.
Transformer Impedance Results
Short Circuit Current
Transformer Comparison
| kVA Rating | Impedance % | Short Circuit (kA) | Voltage Drop | Typical Application |
|---|
Impedance Analysis
Transformer Impedance Formula
Z_actual = (Z% / 100) × (V² / S) I_sc = V / (√3 × Z_actual)
Where: Z% = percentage impedance, V = voltage (V), S = apparent power (VA), I_sc = short circuit current. The actual impedance is calculated from the percentage impedance, then used to determine fault current magnitude.
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