Modeling of Tree Contact Faults in Distribution Networks

Tree contact is a common and potentially hazardous fault in distribution networks. Due to the high resistance and low grounding current associated with tree contact faults, traditional protective devices often fail to detect and trigger at the appropriate threshold levels. However, the presence of undetected tree contact faults for extended periods can lead to dangerous situations, such as the outbreak of wildfires. Existing high-resistance fault models are inadequate in reflecting the mechanisms of tree contact and accurately identifying such faults. This research addresses these limitations by analyzing the physical mechanisms underlying tree contact and developing an improved modeling approach for identifying these faults. The modeling approach considers various factors such as arc characteristics, the influence of temperature on conductivity, and the impact of tree trunk moisture on conductivity. By incorporating these factors into the fault model, a more comprehensive representation of the fault mechanism is achieved. The process of tree contact is divided into multiple stages, and equivalent models are constructed based on the actual physical processes involved. Through comparative analysis with real waveform data, it is demonstrated that the proposed fault models effectively capture the evolutionary process of tree contact faults. The results of this study contribute to the understanding of tree contact faults and their impact on distribution networks. The developed modeling approach, considering arc characteristics, temperature effects, and tree trunk moisture content, provides a more comprehensive and accurate representation of the fault mechanism, facilitating improved fault detection and prevention.