Evaluation and Test of Distance Protection in Cellular Energy Systems by Power Hardware in the Loop Method

Abstract:
In the future, the increased use of converters in the power grid could lead to energy cells consisting exclusively of power electronic feeders. Such energy cells would result in lower short-circuit currents in case of a grid fault. Even in such a system, however, it must be ensured that a faulty feeder is switched off. The interaction between converters and a distance protection is evaluated and tested in this paper as a means of ensuring the supply security. It is found that one and the same converter can have different feed-in behaviors with the same fault. This leads to a non-detectability at the distance protection in the event of unstable converter infeed behavior. These results are useful to understand the interaction between the converter injection during a fault situation and the protection method in such cases. The results show the need for further research in this area and also highlight the necessity for research in comprehensive power systems.