Background. According to Rules for Electrical Installations, all 110 kV and higher power lines must be equipped with a ground wire (GW). However, when lightning strikes GW or a pole and current passes through the pole footing resistance, the potential on it rises and can initiate a back flashover of the line insulation. Such flashovers lead to a short-circuit arc, disconnection of the line, and can also lead to various emergency situations. To protect 110 kV power lines with GW, it is advisable to use additional devices such as multi-chamber arresters. In this regard, it is relevant to conduct tests of new devices, open-type multi-chamber arresters.
Materials and methods. The study and testing have been carried out on unique installations simulating a lightning strike on a power line. The PVG-300K stand is capable of simultaneously supplying a pulse current of up to 60 kA and a line voltage of up to 30 kV to the test sample. The high-voltage PVG generates a voltage pulse of 1,2/50 with an amplitude of up to 2 MV, and the high-voltage AC source allows testing for withstand voltage of industrial frequency up to 200 kV (50 Hz).
Results. A set of electrical tests has been described for a new device manufactured by JSC NPO Streamer, open-type multi-chamber arresters. The breaking capacity on back flashover currents, coordination with line insulation on standard lightning voltage impulses, as well as impulses with a steep front have been assessed. In addition, a test has been carried out on the withstand voltage of industrial frequency.
Conclusions. Opened-type multichamber arresters have successfully passed a total cycle of electrical tests in accordance with the requirements of the PJSC Rosseti standard, as well as technical specifications. Thus, a new device for protection against back flashovers of 110 kV power lines with installed GW can be recommended for practical use to prevent various emergency situations when exposed to adverse atmospheric phenomena.