| Title |
Development of Zigzag Transformer for Unbalance Compensation in Railway Power System |
| Authors |
조규정(Gyu-Jung Cho) ; 박종영(Jong-young Park) ; 정호성(Hosung Jung) ; 한문섭(Moonseob Han) ; 이한민(Hanmin Lee) ; 김형철(Hyungchul Kim) |
| DOI |
https://doi.org/10.5370/KIEE.2022.71.10.1474 |
| Keywords |
Distributed generator; Harmonics; Unbalanced system; Zigzag transformer |
| Abstract |
According to the government's energy policy, distributed generation is likely to be operated in connection with the railway system in the future. Circulating current may occur under unbalanced conditions when using the existing non-standard interconnected transformer for the distributed generation, and this circulating current problem must be solved from the perspective of a distributed power provider in order to accommodate the needs of the power utility. In addition, as the load connected to the power system through the rectifier increases, the harmonic current caused in the neutral wire is also increasing, and there is a need to solve various relevant problems. Therefore, it is necessary to develop an auxiliary transformer (grounding transformer), which has multiple auxiliary roles (reduction of excessive circulating current, protection of non-grounding systems by providing effective grounding).
The developed zigzag transformer has been verified its performance through a characteristic test and an accredited agency certification test after manufacture. In this paper, the design of the zigzag transformer and the modeling of it by using Power System Computer Aided Design (PSCAD) are described. Simple compensation verification of unbalance situation has been also shown. |