Multi voltage converter for rail interoperability

Abstract

Throughout Europe and the World there are many different rail voltage supply levels depending on the region where the infrastructure is. Regardless of the nature of the infrastructure being for heavy or light rail operations, there are differences on the feeding line voltage even in the same country. For light rail is common a DC voltage of 600 V or 750 V and for heavy rail is common 1.5 kVDC, 3 kVDC, 15 kVAC and 25 kVAC. — Different voltage levels constitute a problem for the interoperability, not only within the heavy rail infrastructures, but as well as, between heavy and light infrastructures. To overcome this technical issue, over the years it has been increasing the number of hybrid vehicles that are a fusion between a tram and a train (tram-train), which benefits from electrical systems capable of operating with different voltage levels, thus allowing a multimodal service. This way, these vehicles, can operate as a tram in the light rail infrastructures and as a commuter train in the heavy rail infrastructures.-This paper describes a multi-level converter, to be used in tram-train vehicles, considering standard voltage levels for heavy and light rail operation. This converter will be prepared for 600 VDC, 750 VDC, 3 kVDC, 15 kV 162/3Hz and 25 kVAC 50Hz. It is capable of traction using only a battery pack and an ultracapacitor pack onboard. It is designed to power 6 traction motors installed in 3 bogies. The system is dimensioned to operate in conditions necessary for a tram-train service. A system model was built and simulated and the results show that is possible to operate the vehicle in such conditions with good efficiency and good performance.