Sparse Measurement-Based Fault Location Methodology for Distribution Systems with DGs

The complicated structure and many branches of distribution networks lead to many measuring points and high investment costs for fault location. In this paper, a new fault location method is proposed for active distribution networks with less measuring points. The voltage matrix of main feeder nodes is established with the information of substation and feeder end respectively, and the fault area is initially determined according to the voltage difference matrix. Faults in main feeder are located by the double-ended method. For branch faults, by deriving the relationship between fault voltage and fault current sequence components and establishing the equation of fault voltage about fault resistance and fault distance, only single-ended electrical quantities are needed to achieve precise location of branch faults. The proposed location method requires very few measuring points, and for a distribution network containing only secondary branches, only measuring points at the substation and distributed generations (DGs) are required to achieve fault location. The method has been verified by IEEE 34-bus system to achieve accurate fault location in distribution network with DGs, and its performance is not affected by system grounding modes, and immune to measurement errors, fault resistance and load variations.