The amount of pollutants from stationary sources of businesses classified into 1-3 type in Gyeongju was found to be 0.70 ton/yr for PM-10, 13.95 ton/yr for SO2, and 37.12 ton/yr for NOx ; with respect to area sources, 1.02 ton/yr for PM-10, 13.44 ton/yr for SO2, and 21.10 ton/yr for NOx ; and with respect to mobile sources 963.91 ton/yr for PM-10, 1415.02 ton/yr for SO2, and 5612.70 ton/yr for NOx. This study surveyed the concentration distribution of PM-10, SO2, and NO2 in the air in around Gyeongju and Pohang, and found that high concentration was mainly distributed around Pohang Steel Industrial Complex and the around of mobile sources. In Gyeongju area, SO2 was predicted to increase from 0.002 ppm in 2006 to 0.005 ppm in 2015, and that of NO2 was predicted to increase from 0.004 ppm to 0.010 ppm during the same period. At this point, practicing guidelines to reduce air pollutants and management plan for environmental pollutants should be devised, and also practicing and management programs to protect the stone cultural properties from environmental pollutants and other chemical, physical, and biological factors should be actively introduced.

No abstract

-In microgrid demonstration site, distributed generations can make bidirectional power flows on the system. If an accident occurs, the fault current from the inverter based distributed generation is small. However, the conventional protection scheme in distribution network is designed to operate at high fault current. This means that the traditional protection of distribution network is no longer applicable and new protection methods must be developed. In this paper, for two cases, algorithms for protection coordination of demonstration site is proposed and verified through PSCAD/EMTDC simulation. In first case, protection devices are assumed to have the abilities of directional relaying and communication. In second case, protection devices do not have those abilities. Proposed protection coordination algorithms detect the fault locations and protect the microgrid fairly well.

No abstract