Tree-Related High-Impedance Fault in Distribution Systems: Modeling, Detection, and Ignition Risk Assessment (Review)

Tree-related high-impedance faults (THIFs) in medium voltage distribution systems represent a typical fault, especially where an overhead line crosses a forested area. The arc caused by THIFs could ignite nearby combustibles, significantly increasing the risk of forest fires. THIF detection remains a significant challenge because this type of fault has weak characteristics, as the fault impedance can reach hundreds of kΩ. Many previous studies have investigated reducing the risk of wildfires caused by THIFs. This paper reviews the existing literature on THIF modeling, detection, and ignition risk assessment. The modeling focuses on the distinctions and connections among electrical models of tree structures, traditional high-impedance fault (HIF) models, and THIF models. Detailed reviews and comparisons are conducted on THIF detection methods, encompassing fault analysis, fault feature extraction, and fault identification. The experiments and methods for assessing THIF ignition risk are also introduced and discussed. The review reveals critical research gaps. In modeling, there is a lack of frameworks that simultaneously elucidate underlying mechanisms and support detection algorithms. In detection algorithms, the existing methods have not been adequately validated under complex environmental conditions. In ignition risk assessment, current studies do not account for a comprehensive range of influencing variables. Finally, this paper proposes future research directions for THIF, aiming to provide a comprehensive reference for researchers and practitioners in this field.