Analysis of the STATCOM/Balancer Robustness in Railway Applications

Electrified railways are supplied by transmission and/or distribution grids where different power quality issues can occur. In particular, voltage sags and overvoltages can affect not only the catenary voltage and trains operation in transformer-based substations but also power electronics converters connected to those grids. Today, more and more converters are needed to improve the railway system operation and most of them can be affected by phenomena occurring in the ac voltage. This paper focus the STATCOM/Balancer operation connected to the three-phase ac grid and analyses its robustness against voltage sags and overvoltages using a specific global control approach.