1. What is Transformer Impedance?

Transformer impedance is a measure of the opposition that a transformer presents to alternating current. It is calculated from efficiency, voltage, and power parameters, providing insight into the transformer's performance characteristics.

2. How Does the Calculator Work?

The calculator uses the transformer impedance formula:

Where:

• \( Z \) — Transformer impedance (ohms)
• \( \text{Efficiency} \) — Transformer efficiency (unitless, 0-1)
• \( V \) — Voltage (volts)
• \( P \) — Power (watts)

Explanation: The formula approximates transformer impedance based on energy losses represented by (1 - Efficiency) and relates it to voltage squared divided by power.

3. Importance of Transformer Impedance

Details: Transformer impedance is crucial for system protection coordination, voltage regulation, short-circuit analysis, and ensuring proper transformer performance in electrical systems.

4. Using the Calculator

Tips: Enter efficiency as a decimal between 0 and 1, voltage in volts, and power in watts. All values must be positive with efficiency not exceeding 1.

5. Frequently Asked Questions (FAQ)

Q1: What is typical transformer efficiency?
A: Modern transformers typically have efficiencies between 95-99% (0.95-0.99), with larger transformers generally being more efficient.

Q2: How does impedance affect transformer performance?
A: Higher impedance provides better short-circuit protection but can cause greater voltage drop under load. Lower impedance provides better voltage regulation but higher fault currents.

Q3: When is this approximation most accurate?
A: This formula provides a reasonable approximation for typical power transformers operating near their rated conditions.

Q4: Are there limitations to this calculation?
A: This is an approximate method. For precise impedance values, manufacturer specifications or direct measurement should be used.

Q5: How does temperature affect impedance?
A: Transformer impedance can vary with temperature due to changes in winding resistance, though this calculation assumes standard operating conditions.