Why transformers connected in parallel should have same voltage ratio?
A
To avoid full load circulating current
B
To avoid no-load circulating current
C
To avoid other losses
D
To avoid all type of currents
Correct Answer: To avoid no-load circulating current
The transformers must have the same voltage-ratio to avoid no-load circulating current when transformers are in parallel on both primary and secondary sides. Since the leakage impedance is low, even a small voltage difference can give rise to considerable no-load circulating current and extra I2R loss.