Advantages of transformer parallel operation

The two or more than two transformers, respectively, the secondary side were connected to their respective public bus, while the load power supply. The company is located in:
Advantages:
(1) improve operational efficiency;
(2) improve the reliability of power supply;
(3) to facilitate expansion.
2.the ideal conditions for parallel operation
(1) the same ratio;
(2) the same group number of the link group;
(3) the output current of the transformer with the same phase;
(4) The impedance voltage of each transformer is equal.
The secondary side of two transformers operating in parallel forms the circuit.
If the coupling group and variable ratio are equal, you can ensure that there is no loop in this loop.
A small secondary voltage difference will also cause a large circulation in the return road, so the ratio allows only a very small deviation (0.5 to 1)%