Parallel operation of three-phase transformer for star-delta and delta-delta connections / Mohamad Hisyam Mansor

Parallel operation of transformer involves two or more transformers connected to carry a common load. In order that two or more transformer may operate satisfactorily in parallel it is necessary to fulfill their requirement. The criteria required for parallel operation of transformers are the voltage ratio, impedance, phase sequence and also the· polarity. The aim of this report is to investigate the requirement for parallel three-phase transformer and the condition when loading with the combination of load. To achieve this, several tests had been done including polarity, phase sequence, open circuit, short circuit and load tests.