Research and Application of High‐Sensitivity Grounding Fault Startup Method for Forest and Grassland Distribution Networks Based on Zero‐Sequence Voltage Vector

ABSTRACT Single‐phase ground faults in forest and grassland distribution networks pose a risk of igniting wildfires, necessitating enhanced fault detection and handling. However, the transitional resistance of faults such as tree‐line faults is generally high, and the current mainstream fault detection technologies for ground faults lack sufficient high‐resistance detection capability, which is inadequate for wildfire prevention scenarios. This paper proposes a high‐sensitivity ground fault detection method based on zero‐sequence voltage, which can enhance the high‐resistance detection capability up to 100 kΩ. By analysing the general characteristics of ground faults in distribution networks, the relationship between fault features and system network parameters is revealed. The structural characteristics of distribution networks in forest and grassland areas are summarised, and a method for actively enhancing fault zero‐sequence voltage signals is proposed. Based on zero‐sequence voltage, a high‐sensitivity ground startup is constructed and methods for achieving startup sensitivity, reliability and selectivity are explained. Finally, the performance of the proposed method is validated through simulations and field application cases.