Current protection against earth faults in networks 6 - 10 kV

The work is devoted to the problem of improving zero-sequence current protection (TZNP) from single-phase ground faults (OZZ) of electrical networks 6-10 kV. The problem of selective and sensitive protection against SPC is caused by low fault currents and different modes of neutral grounding used in 6-10 kV networks, and above all, by the intermittent arc character of most of the earth faults. The main content of the work is devoted to solving problems related to the development and application of various methods for studying the dynamic modes of the functioning of TZNP: mathematical and physical and mathematical modeling, experimental studies of the influence of electromagnetic transient processes during SPP on the functioning of various versions of TZNP, application of the results to improve the design methodology of TZNP, development of optimal algorithms for digital protection against SPL on a microprocessor base. The research results are of scientific and practical value for specialists working in the design, development and operation of earth fault protection for medium voltage electrical networks.