| This paper is focused on the transformation of a classical DC-traction substation with twelve-pulse uncontrolled rectifier into an active traction substation by adding a dedicated system for active filtering and regeneration called SISFREG. The connection of SISFREG to the ACside is performed in the primary of the traction transformer via a passive coupling filter and a recovery transformer, whereas an active separating circuit ensures the connection to the DC-traction line. The new functions added to the DCtraction substation lead to the increasing the energy efficiency of the whole system in both traction and braking regimes of the vehicles’ traction motors. The control of the current provided by the shunt active filter, which is the main component of SISFREG, is achieved in indirect mode, by means of the current upstream the point of common coupling. In the generation of the set current, the concepts of the Fryze-Buchholz-Depenbrock theory are implemented. Thus, an active current is always imposed at the power supply side and the current control loop guarantees almost sinusoidal current and global unity power factor. A complex Simulink model of the whole system, including facilities for energetic analysis, has been developed and the simulation results show good performances in both steady-state and dynamic regimes. |
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