What are merits and demerits of transformer connected in parallel?

Answer 1

Followings are merits and demerits of parallel operations of Transformers:

Merits

1. Increasing load demand on substation can meet by connecting transformers in parallel.

2. Maintenance of individual transformer with low rating (Instead of one Big transformer with high rating)becomes easy and can be done without affecting power supply.

3. In case of any fault, faulty transformer can be removed from the system and others may continue feeding the load.

4. Power reliability of substation is increased.

Demerits

1.Parallel operation needs very much attention and correctness.

2.Phase sequence , Voltage Ratings , % impedance drop and polarities these few things comes in picture which needs to be taken care when doing parallel operation.