Electrical Performance Verification Study of Underground Structures Including Electrical Distribution Equipment

Due to the increasing demand for underground installation of ground equipment, KEPCO has been researching the installation of Underground Compact Distribution Stations (U-CDS). To install and operate U-CDS in the distribution system, it is necessary to establish relevant standards and design and operation criteria. Therefore, this paper discusses the test method of IEC 62271-202 to establish its standard. This standard mainly comprises dielectric tests, temperature rise tests, short-time/peak current tests, and internal arc tests. However, each electrical distribution equipment has already been tested for dielectric, short-time current, internal fault arc, and temperature rise tests. Since U-CDS requires all equipment to be gathered in one place and operate safely, it is necessary to test the interconnections. As a result of the tests, some tests satisfied the standards, but others did not. Since these tests have not been performed before, additional research on the standards and test methods will be needed.