How do you calculate the impedance of a 3 phase transformer?

Sample calculations for a three phase transformer rated 500kVA, 4160:480, 60Hz, 6\% impedance:

1. Transformer reactance Xt = (kV2/MVA) x \%Z/100 = (0.482 / 0.5) x 0.06 = 0.027648 ohms.
2. Rated secondary current = 500,000 / (480 x 1.732) = 601.4 amps.
3. Actual Load current = 300 amps.

How does the impedance on the secondary if transferred to the primary?

The Reflected (referred) impedance (the impedance looking into the primary side of the transformer) When we move an impedance from the secondary to the primary side of the transformer we multiply by the turns ratio squared.

How is impedance transferred in a transformer?

The simplest way to match load impedance in AC circuits is to use a transformer — a highly efficient device that transfers electrical energy from one circuit to another through electromagnetic induction: Two coils of wire (windings) are wrapped around an iron or ferrite core, and when the primary winding experiences …

When secondary resistance is referred to a primary side?

In fig -2 shows , The secondary resistance is transferred to primary winding and secondary winding is resistance less. And the total resistance at primary winding is ( R1 + R2/K2 ) which is known as the equivalent resistance of the transformer as referred to primary .

When expressed in Pu values the equivalent impedance of a transformer referred to primary and secondary is the same?

The per unit impedance of a transformer is the same whether computed from primary or secondary side so long as the voltage bases on the two sides are in the ratio of transformation (equivalent per phase ratio of a three-phase transformer which is the same as the ratio of line-to-line voltage rating).

What is the relation of secondary winding leakage reactance and secondary circuit impedance?

5. What is the relation of the secondary winding leakage reactance and secondary circuit impedance? Clarification: The secondary winding leakage reactance is directly proportional to the secondary circuit impedance.

Where equivalent impedance of transformer referred to secondary can be derived?

In a similar way, the approximate equivalent circuit of transformer referred to secondary can be drawn. Where equivalent impedance of transformer referred to secondary, can be derived as Electrical4U is dedicated to the teaching and sharing of all things related to electrical and electronics engineering.

What is meant by impingance in a transformer?

Impedance referred to primary means that we’re shifting the secondary resistance and reactance to the primary. This shifting has to be done keeping in mind certain conditions so that the overall performance of the transformer remains intact.

What is the load voltage of secondary winding of a transformer?

Current of secondary is I 2. So the voltage E 2 across secondary winding is partly dropped by I 2 Z 2 or I 2 R 2 + j.I 2 X 2 before it appears across load. The load voltage is V 2. The complete equivalent circuit of transformer is shown below.

Is the value of impedance same for primary and secondary windings?

The value of percentage impedance is the same for both windings as it is the percentage of rated voltage. However, the value of the rated current will be different for primary and secondary windings. Accordingly, value of short circuit current will also be different for primary and secondary windings.