<p>A railway power flow controller is a power electronics-based system that controls and manages the flow of power in an electric traction power supply system. The aim is to maintain power flow such that power quality indices are within prescribed limits. This paper proposes thyristor-controlled LC (TCLC) coupling in a railway power flow controller (RPFC) to reduce the power converters’ DC link requirement and volt-ampere rating. Accordingly, an adaptive impedance-coupled RPFC is proposed for a V–V transformer-based railway power supply system. The proposed system aims to draw balanced power from the source at unity power factor under highly variable single-phase loads. The control algorithm is further proposed, to derive the reference current for the power converters without calculating the active and reactive powers. An adaptive firing angle adjustment algorithm is also proposed for TCLC control. Operational feasibility of the proposed topology and its control algorithm is verified in a 60 MVA traction substation using a real-time hardware-in-loop experimentation. The power circuit is implemented in a real-time simulator, and the control algorithm is developed using an ARM Cortex-M4 32-bit microcontroller.</p>