Stability testing of converter coupled systems by power hardware in the loop equipment

Abstract:
Converter coupled systems offers the advantages of flexibility in operation, but there are also challenges in their application like stability limits during special grid condition, such as line faults. To ensure the stability of electrical energy system with converter coupled systems during such special grid situations, it is necessary to check the stability behaviour at different grid conditions. This paper investigates a realistic grid situation and uses a modern approach for testing the behaviour of converter-based generation for such a realistic situation. The used power hardware -in-the-loop (PHIL) systems ensures a simpler, more realistic and also more comprehensive validation of the system behaviour. This research deals with a three-phase fault and shows how the whole system is behaving by disconnecting the faulty line. This fault and the clearing behaviour lead to unsuspected reactions of the converter coupled system where the system could get an error and switch off which demonstrates the importance of such test systems for the energy network of the future.