A hierarchical fault location method for AC collection lines in wind farms

The collection lines of wind farm AC systems are distinguished by a substantial number of interconnected wind turbines, abbreviated lines, and intricate topologies, which complicates the process of fault location. In order to address the aforementioned challenges, this paper proposes a wind farm collection line asymmetrical ground fault location scheme based on zero-sequence components. This paper establishes a zero-sequence grid model for wind farms under unbalanced fault conditions and analyses the zero-sequence fault characteristics of AC collection line grounding properties. Secondly, in order to address the impact of complex topology on fault location and improve location accuracy and efficiency, a hierarchical fault location algorithm is further proposed. The process of acquiring fault segments is predicated on the foundation of zero-sequence voltage fault components. The fault equation is constructed using zero-sequence measurement information from both ends of the fault section, and an optimisation algorithm is used to determine the exact location of the fault. The MATLAB simulation results demonstrate the efficacy of the proposed scheme in overcoming the effects of uncertain factors, such as transition resistance and fan control. The scheme effectively achieves precise location of asymmetrical faults in busbars.