Application of Energy Storage System for Seoul Metro Line 2,3,4

초록

The recent environmental protection trend requires more strict energy saving, therefore every transportation system should reduce energy consumption to the minimum value. High-efficiency operation system, energy saving and CO2 emissions shall be addressed as important issue in railway system. These issues are the most essential factors of railway, major public transportation system. For such new energy saving, the ESS is considered for storing energy. Energy saving is possible by efficient use of regenerated energy. Regenerated energy is recycled amongst vehicles by mean of charge and discharge corresponding to powering and braking of electric vehicle operations. This energy saving contributes to cut CO2 to reduce greenhouse gas emissions. Recycling regenerated energy demonstrate significant effect on peak cut of consumption energy in railway substation. Absorption of excess energy avoids regeneration failure due to high traction voltage. In lines in which regenerative vehicles are used, regenerated energy is recycled amongst vehicles for efficient use. However, about 40% of excess energy generated by braking vehicles will be wasted when no powering vehicle is existed within effective distance. This dissipation constitutes resistance heat at electrical brake and frictional heat at mechanical brake. The ESS is simple solution to store the braking energy in an EDLC and recycle it to powering vehicle. The ESS as one of railway power traction system will be installed in the substation. This paper presents energy saving obtained by applying the energy storage system to Line 2,3,4 of Seoul Metro.