Subway power system

Power line

• Overview It refers to extra-high voltage (154KV) raceway installed to transfer power from KEPCO substation to subway substations, and 2 lines are installed in overhead or underground

Substation facility

• Overview This facility converts the extra-high voltage (154KV) received from the power line to alternating current (55KV) suitable to the railway, and supplies to or disconnected from catenaries.
• Facility
  • Substation (S/S) : Convert extra-high voltage (154KV) received from the power line to 55KV in order to supply the power to catenaries
  • Sectioning post (SP) : it is installed between substations, and connects or disconnects power for both sides.
  • Parallel feeding post (PP) : It is installed in 8 ~ 10Km interval with auto-transformer to reduce communication inductive disturbance created from AC traction line and compensate the voltage drop
  • Harmonic reduction facility : An attached facility installed in substation to maintain harmonic wave created from AC subway facilities under the value (1.5%) required by KEPCO
  • SCADA System : A computer system that controls and monitors power supply systems in a centralized place, and collects, analyzes, and manage relevant data.

Traction line

• Overview
  • Raceway such as catenary that contacts to vehicle pentagraph and supplies electricity
  • The dynamic characteristics of catenary and pentagraph are critical factor that affects on the speed of the electric car. Individual countries apply their own know-how to the traction line system.

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  General view of general railway catenary

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  General view of high-speed railway catenary

Power distribution system

• Overview
  • It supplies power to railway station, tunnel facilities, signaling, and communication system, and refers to raceways, switchgear, and their attached devices.