The possibility of increase or decrease of demand in future can never be ignored in
power system.
Provision of connections of the parallel transformer to meet the increased demand keeps the system flexible.
Installation of the signal transformer of greater capacity by forecasting future demand proves unnecessary investment, which may be worth mostly may not.
In case of decreases in demand capital investment and its return can be balanced by simply removing the transformer.
Primary windings are connections to supply bus bars and secondary windings are connections to load bus bar.
Connections which must be fulfilled for parallel operations of the transformer are,
- Same KVA rating.
- Same percentages impedances and X/R ratio.
- Same voltage ratio and turn ratio.
- Same polarity.
- Same phase sequences in case of 3ᵩ transformers.
- Same frequency