The same polarity condition is essential in parallel operation because:

Question

Question

This question was previously asked in

RRB JE EE 22 Apr 2025 Shift 2 CBT 2 Official Paper

Answer 1

Concept

The same polarity condition for the parallel operation of a transformer is necessary because:

Circulating Current: When transformers have opposite polarities, their secondary EMFs act in opposition, creating a closed loop that allows a significant current to flow even without a load. This circulating current can damage the transformers and the system.
Load Sharing: With the same polarity, the EMFs of the transformers add constructively, allowing them to share the load effectively. Opposite polarity would result in a destructive interaction, preventing proper load sharing and potentially overloading one transformer.
Short Circuit Prevention: Incorrect polarity can lead to a short circuit in the parallel connection, causing severe damage to the equipment.