A versatile test bench for grid integration investigations of back-to-back wind energy conversion systems

This paper presents a versatile test bench for the investigation of the power electronics converter and its control for different wind energy conversion concepts. A three-level back-to-back converter connects a drive train consisting of an induction machine and a synchronous machine to the grid. 4-quadrant operation is feasible on both sides controlling the converter either in 2- or 3-level mode. The test bench is scaled to a power level of 10kW, where the scaling also includes the stiffness of the drive train shaft allowing to investigate mechanical resonances of low speed machines.