Trackside converter as a public grid replacement

This paper describes a converter that converts the DC traction supply voltage on a catenary or 3
^rd
rail into a 3-phase AC voltage that can be used as a replacement for a connection to the public grid. The input requirements are based on the electrical constraints of traction supply systems, which have a wide variation in the voltage level. The output requirements are specified by the electrical constraints of public grids, where harmonics are a point of attention. The design is based on a standard 2-level IGBT inverter and combined with input and output filters. A transformer is used for voltage adjustment and the creation of an earthed neutral point. Measurements on a test set up showed that the developed system meets the requirements of the public grid. It was experienced however, that capacitive loads, e.g. input filters of LED drivers cause large inrush and ripple currents requiring special attention and measures. A pilot converter is installed next to a tramway to supply LED lighting along the track. This has confirmed that the Trackside Converter system is suitable to act as a replacement of a public grid connection.