Abstract
UDC 537.622.4: 621.316.9
DOI https://doi.org/10.52577/eom.2024.60.6.71
The article considers the issue of protecting substation equipment and overhead lines from high-frequency lightning surges using a device based on a nanocrystalline tape made of an amorphizing alloy. The object of protection is a substation that uses a cable insert between the overhead line and the substation input. A distinctive feature is the fact that the 35 kV overhead line is made on pores for 110 kV overhead lines. A high danger of surges is shown with such a configuration of the overhead line, which includes a cable insert. A method for protecting against high-frequency surges is proposed using a device operating on the use of an anomalous skin effect – a frequency-dependent device, due to the presence of a ferromagnetic material applied to the conductor. The device significantly increases its active resistance when passing high-frequency signals. It is shown that the use of a frequency-dependent device makes the incident high-frequency pulse safe for both the turn insulation and the insulation of the cable insert. The issue of changing the dimensions of the protective device for selecting the necessary parameters of resistance and inductance is considered. The issue of thermal stability is also touched upon in connection with the use of ferromagnetic material in the design of a frequency-dependent conductor. It is shown that under the action of lightning over-voltages and short-circuit currents, destruction of the material or changes in its properties will not occur. The results presented in the article will allow the use of a new device for protection against high-frequency lightning over-voltages, as well as improving its design for specific technical requirements.
Keywords: lightning over-voltages, short impulses, overhead power lines, cable lines, frequency-dependent device, thermal impact.