Fault ride through constrained protection scheme for distribution networks with DFIG-based wind parks

The main protection of distribution networks is based on overcurrent relays (OCRs). Due to the slow operation of these relays, some distributed generations (DGs), e.g. wind parks, may be unable to meet the fault ride through (FRT) requirements, which leads to unnecessary generation loss during faults. This paper proposes a new protection scheme for distribution networks that considers the FRT requirements of DFIG-Based wind parks. This is achieved by considering both the protection coordination constraints and FRT requirements in a single protection scheme. Considering the FRT requirements, the new method determines whether each overcurrent relay operates fast enough. If not, the proposed scheme determines a suitable solution for each relay to facilitate a faster operation. The proposed method is tested on the IEEE 33 bus test network and compared with conventional methods. Its superior impact on improving the FRT requirements and hence preventing unnecessary disconnection of DFIG-Based wind parks during short circuit faults is demonstrated through simulation results, proving by this its applicability and efficacy.