Auxiliary power convertors for locomotives

The use of squirrel cage motor for auxiliary loads in railroad applications makes it necessary to have a conversion system aboard the locomotive or the train. This system has to convert a 1-phase ac or a dc voltage into a 3-phase 50 or 60 Hz voltage. This paper presents solutions built on power electronics. Compared to rotating equipment the power electronic solution offers important advantages regarding weight, losses and mechanical flexibility. The transient behaviour at pantograph bounces and switching in the load is also dealt with.