Dead-beat control for a single-phase 50-kW, 16.7-Hz railway-grid representation inverter featuring variable grid parameters

To investigate railway grid interaction a fully controlled grid representation is essential in order to emulate line-current harmonics and grid impedance. Based on a grid representation - realised with a four-quadrant inverter - advanced control concepts for the power train of railway traction vehicles can be developed. In this paper the focus lies on the design of a dead-beat control of the grid inverter, including system analysis, set-point value computation, details of the control design, observer and compensation of nonlinear effects of the inverter. Measurement results for stationary and dynamic behavior at load-steps are presented, verifying proper operation.