Single-phase 50-kW, 16.7-Hz railway-grid Lab Representation using a DC-excited slip-ring induction generator

Railway grid interaction is a major concern when developing the power train of a railway traction vehicle and its control. Two main areas have to be taken into account: line-current harmonics and inter-harmonics are limited with often extremely low limit values compared to nominal current, respecting the properties and safety issues of railway track circuits. Grid stability is influenced by the varying grid impedance seen by the moving vehicle, in connection with varying resonances, influenced by other vehicles and the actual grid configuration. The development of an optimized control scheme for the power train of a railway traction vehicle operating at the 15-kV, 16.7-Hz-grid-widely used in central Europe-requires advanced simulation tools as well as suitable laboratory experiments for verification. This paper is focused on the slip-ring induction generator feeding the 16.7-Hz single-phase laboratory grid, featuring the behavior of rotary converters and the special provisions taken to enable single-phase operation. Measurement results for stationary and dynamic behavior with different loads are presented.