Demonstration of the LVDC distribution system in an island

Abstract

This study introduces and describes a demonstration island of low-voltage direct current (LVDC) distribution system. The LVDC distribution system is planned to be constructed in an island of South Korea named Geochado by a project of KEPCO (Korea Electric Power Corporation). In this study, the network design of the demonstration island is proposed. A new DC network will be installed to demonstrate the LVDC distribution system and is planned to operate with the existing AC network. In addition, this paper presents the composition of loads for the DC network demonstration and distribution energy resources (DER) containing renewable energy resources. A variable speed function is planned to be developed for fuel efficiency operation. To calculate optimal DER capacity, HOMER microgrid economic analysis tool is used. Optimal HOMER results are presented with several cases. The final DER capacity is selected by considering the cost, stability and recent weather conditions. The energy management system is designed for efficient monitoring and control of LVDC distribution system. In addition, heat management system, power management system and automatic demand response are applied for demonstration. Each system interface method and a communication method for systems and field devices are proposed. Finally, the operation strategy for the LVDC distribution system is proposed in this study.