Power Hardware-in-the-Loop Validation of Grid-Forming Control and Current Limitation for Start up of Induction Motors in Microgrids

The start of induction motors in converter based microgrids poses particular challenges for grid-forming converters due to the limited over-current capabilities. To avoid undesirable over-current operation of the converters during start up, suitable current limitation methods are required to limit both the provided amplitude and the provided angle of the grid-forming control in an appropriate way. In this paper, a grid-forming control with voltage phasor based current limitation is validated using power hardware-in-the-loop for the case of induction motor start up in an exemplary industrial microgrid. For validation, the two different current limiting prioritization methods of amplitude and angle prioritization are analyzed in case of start up of an induction motor at different torques.