Current injection based Power Flow Algorithm for bilevel 2×25kV railway systems

In the present paper, an iterative current injection based algorithm is presented for solving 2×25kV bi-voltage power systems with embedded autotransformers. This kind of systems are used for feeding most of the high-speed trains. The proposed methodology minimises the number of unknowns without simplifying the autotransformers model, conserving the original topology of the network. The system of equations stated at each iteration is linear and most of its terms are constant. Those that must be updated at each iteration have been minimised to reduce the computational burden. The proposed algorithm is accurate, robust and much faster than Newton-Raphson based solvers.