Faulty Feeder Identification Method Considering Inverter Transformer Effects in Converter Dominated Distribution Network
Xiangxiang Wei, Xiaowei Wang, Jie Gao, Dechang Yang, Kewen Wei, Liang Guo, Yanfang Wei
Abstract
With the increase in inverter interfaced distribution generations (IIDGs), converter-dominated distribution networks (CDDNs) are expected. When a single-phase-to-earth (SPE) fault occurs in a CDDN, since the inverter transformer effects can affect the transient fault characteristics of fault signals, the existing faulty feeder detection techniques may not be applicable. This paper focuses on the inverter transformer effects on transient zero sequence currents (TZSCs). First, the inverter transformer effects on TZSCs are analyzed, and the analytical expressions of TZSCs are derived. It is found that the transient fault characteristics in TZSCs may become weak by considering the inverter transformer effects. As a result, the accuracy and reliability of faulty feeder detection face more challenges. To address this issue, a novel faulty feeder identification method based on the first order accumulated generating operator (AGO) method and improved cosine similarity is proposed. The effectiveness and applicability of the proposed method are validated in the converter-dominated distribution network. Additionally, the field test results also indicate the feasibility of the proposed method.