Current Limitation Methods during Grid Faults for Power Converters with Fictitious Synchronous Generator Control

Abstract:
The converter control method of a fictitious synchronous generator can be used to supply a microgrid. In a previous work the black-start capability and stable operation of two parallel converters has been demonstrated. However, during grid short-circuits high overcurrents, which can damage the converter, were observed. Therefore, new methods to decrease and limit the converter currents have been developed. Firstly, optimisations to the existing model are shown and the short-circuit behaviour is analysed in detail. Afterwards, different methods for current limitation are presented. Finally, simulation results of the current limitation are shown and compared to the previous model.