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Impedance Result

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Calculation Formula

Percent impedance is calculated by dividing the impedance voltage by the rated voltage and multiplying by 100.

%Z = (Impedance Voltage / Rated Voltage) × 100

Typical transformer impedance ranges from 3% to 15% depending on the application and size.


The Transformer Impedance Calculator is a helpful tool for calculating the percentage impedance of a transformer. This value is important in the design and analysis of electrical systems, especially for load sharing and fault level calculations.

What is Transformer Impedance?

Transformer impedance represents the internal resistance and reactance inside the transformer. It limits the amount of current that flows during short circuits and affects voltage regulation. Impedance is expressed as a percentage of the transformer's rated voltage.

Impedance Formula

Impedance (%) = (Impedance Voltage / Rated Voltage) × 100

Example:
Impedance Voltage = 6 V
Rated Voltage = 100 V
Impedance (%) = (6 / 100) × 100 = 6%

Why is Transformer Impedance Important?

  • Helps calculate fault current during short circuits
  • Useful in parallel operation of transformers
  • Affects voltage drop and load sharing
  • Essential for power system protection and stability

Applications of This Calculator

  • Electrical engineering analysis
  • Transformer design and manufacturing
  • Power system fault level studies
  • Planning transformer parallel operations

Quick Tips

  • Always use the same voltage units when entering values.
  • Transformer impedance is usually provided on the nameplate.
  • Higher impedance reduces short-circuit currents, but increases voltage drop.

Conclusion

Our Transformer Impedance Calculator makes it easy to find the impedance percentage of a transformer. Whether you are a student, engineer, or technician, this tool can assist in making informed decisions about transformer sizing, protection, and performance.