Fault Section Location for Resonant-Grounded Distribution Networks by DC Attenuation Components of Grounding Wire Currents and Transient Polarity of Zero-Sequence Currents

Fault section location in distribution networks is a key technology for enhancing power supply reliability and fault recovery efficiency. However, the existing fault section location techniques all have certain limitations, such as being affected by fault types and working conditions. Therefore, to achieve fault section location in different fault types for resonant-grounded distribution networks, such as grounding faults and arc faults, this paper proposes a comprehensive method based on DC attenuation components of grounding wire currents and transient polarity of zero-sequence currents. Firstly, by analyzing the cable distribution model, it is found that the DC attenuation components of grounding wire currents in healthy and fault lines are different. The transient polarities of zero-sequence currents of healthy and fault lines are opposite. Based on this, a fault section location method using DC attenuation components is proposed. Meanwhile, to improve the accuracy of the location method, a fault section location method based on transient polarity is also developed. Then, a high-reliability fault section location method is formed by complementing each other through two methods. Finally, 10 kV distribution network fault simulation models are established using PSCAD/EMTDC and RTDS. The experimental results show that the proposed method can accurately locate the fault section under different fault types, fault angles, fault resistances and noise conditions.