Power Electronics Converter Application in Traction Power Supply System

The electrified railway systems have been spreading all over the world. In big cities, metro or light rail transit railway networks have been constructed extensively. Expansion of this enormous dynamic electric load has been created huge amount of stress on the power grid. Generally, the speed drives, power conversion equipment or frequency converters inject harmonic in to railways power supply system. These harmonics seriously disturbs other electrical systems or generate a high frequency electromagnetic fields in neighboring electrical equipment as well as traction network signaling system. However, new developments in power electronic converter enable efficient and flexible conditioning of electrical energy in the application of railway power system. Power electronics, already previously being a pioneer for progress of traction vehicles, brought forth an ultimate standardization of the traction power supply system. Today, the spectrum of power electronic converters application in the traction system spread in many areas including power electronics based traction transformers, auxiliary power supply systems, rectification, integration of regenerative braking, reactive power compensation and voltage regulation and traction motor controls. This paper reviews the applications of semiconductor based power electronic devices in electrified railway system and illustrates some major application areas.