Background. The existing methods of fault location (FL) on power lines are often unable to provide the required accuracy and are unstable to the influence of metering-distorting factors. The main source of errors of the FL devices is the primary current and voltage transducers. Using innovative current and voltage sensors (including Rogowski coils for physical measurement of the primary current derivative) as part of digital measuring transformers allows significant improvements in the accuracy of measuring electrical values during short-circuits. The aim of the work was to develop an enhanced accuracy FL function as part of an information system (IS) that takes into account the characteristics of non-traditional primary converters and, in general, digital current and voltage transformers.
Materials and methods. The methods of the electrical circuit theory, mathematical simulation and physical-mathematical modeling are used. The computer experiments are carried out in the modern modeling systems Matlab + Simulink and RSCAD, and the physical and mathematical modeling – in the real-time modeling complex RTDS. For modeling power transmission lines, the specific parameters were assumed to be known and unchanged.
Results. The developed FL function differs from its analogs as it uses information signals from digital current and voltage transformers, is characterized by operation stability under the influence of some metering-distorting factors (presence of transient resistance, changes in electrical load, breakdown phase, presence of capacitance of phases to earth, etc.) and an error not exceeding 8 % (at large distances and in the presence of transitional resistance in short-circuit locations) or 3 % (in the absence of metering-distorting factors). A prototype of the IS with the FL function has been designed and experimentally tested.
Conclusions. The developed FL function allows increasing the accuracy of short-circuit location determination and reducing the time of finding the fault. Fault location IS data can be used by the operating personnel of electrical networks. The reliability of the obtained results is determined by the methods of the classical electrical circuit theory and the theory of electromagnetic transients in electrical power systems, and by the convergence of the results obtained in the study of the function accuracy in different modeling complexes.