A Protection of interconnection transformer for DG in Korea distribution power system

The interconnection transformers are used to interconnect a distributed generation (DG) units with the existing power system. The transformer connections play a key role in how the DG unit affects the utility system and how the utility system affects the DG unit. The interconnection of DG with the power distribution system, however, creates many challenges for utilities. These challenges are related to the types of transformer connection and ground for interconnecting DG. This paper discusses the effect of the transformer connection and ground on the Korea distribution power system. In addition, this paper analyzes the causes of protection interruption that occurs frequently in Korea distribution power system with interconnecting DG. The paper also suggests the protection configuration of interconnection transformer to solve the protection interruption.