how to measure power transformer impedance?

To measure a power transformer’s impedance, you can use the short-circuit test method. First, short the secondary winding and apply a low voltage to the primary winding until rated current flows. Measure the voltage and current during this test. The impedance can be calculated using the formula ( Z = frac{V}{I} ), where ( V ) is the applied voltage and ( I ) is the measured current. This method provides the transformer’s equivalent impedance under load conditions.