Propulsion system for Kwachon line of Korean National Railways (application of PWM converter to commuter car)

With the development of the Korean economy and the population concentration in metropolitan areas, metropolitan Seoul is suffering from heavy traffic jams and needs to urgently expand its railway network as a mass transit system. In connection with this, the Kwachon Line is to be constructed to connect the Korean National Railways (KNR) line and Seoul Subway (SMSC) Line No. 4, and new dual-voltage electric multiple units (EMU) have been produced to offer a run-through service to the KNR line having an aerial power line of 25 kV AC and 60 Hz and the SMSC line having an aerial power line of 1500 V DC. This dual-voltage electric car is the first commuter-train adopting a PWM power converter-PWM inverter method to provide high frequency and power factor and to reduce high frequency. A reverse conducting GTO is adopted for the main circuit switching elements to miniaturize and reduce the number of components. Since this system is the first PWM power converter-PWM inverter method in Korea, it is structured with particular attention to its maintenance and handling. This paper introduces the outline and characteristics of this system.