A Comprehensive Study of a Railway Power Conditioner for 25 kV Substations with Scott and V/V Transformer

The 25 kV AC railway power supply is widespread worldwide, but it produces a voltage unbalance on the upstream three-phase electric power transmission grid. Nowadays, the railway traffic increase exacerbates this unbalance issue. The use of power electronic converters appears to be an appropriate response. This paper first recalls the principle of the Railway Power Conditioner (RPC). This converter redistributes power between two railway sectors of the same substation. The study focuses on substations with either Scott or VV transformer arrangements. Simulations, considering the actual power consumption of a substation, are carried out. The sizing of converter is then discussed, taking into account the type of transformer (Scott or VV) and a control with a partial or total compensation of voltage unbalance.