Analysis of Three Phase Transformer Parallel Operation and Circulating Current

Parallel operation of transformers is needed when the load is increased and it exceeds the capacity of the existing transformer, if multiple transformers are running in parallel and a fault occurs in one transformer, then the other parallel transformers still continue to serve the load. The reliability is increased with parallel operation than to have a single larger unit. The cost associated with maintaining the spares is less when two transformers are connected in parallel. For parallel connection of transformers, primary windings are connected source bus bars and secondary windings are connected to the load bus bars. The conditions of connecting transformers in parallel and loading considerations when turn ratios, impedances and MVA ratings are different. Load division or load sharing store excess electrical power during low demand periods for release as demand rises. The goal would be for the power supply system to see a load factor of 1. In this thesis, two 100MVA transformers are connected in parallel. The 230 kV to 33 kV in Substation is used as the location to study and analyze the load division and circulating current of parallel transformer operation. The parallel operation provides more reliability. So, it is used in a substation. The value of the load division and circulating current are calculated with the case of the parallel transformer in this paper. Zin Wah Aung "Analysis of Three Phase Transformer Parallel Operation and Circulating Current" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26593.pdfPaper URL: https://www.ijtsrd.com/engineering/electrical-engineering/26593/analysis-of-three-phase-transformer-parallel-operation-and-circulating-current/zin-wah-aung