No abstract

This paper presents the results of a comparative analysis of the dielectric strength of disconnecting vacuum interrupters operating on air and helium. The breakdown voltage Ud was measured in the pressure range from 8.0 × 10−4 Pa to 3.0 × 101 Pa for air and from 8.0 × 10−4 Pa to 7.0 × 102 Pa for helium, while varying the interelectrode distance from 1.0 to 5.0 mm. Dedicated laboratory workstations were used to determine the actual pressure values in the vacuum interrupters tested and to precisely measure and record the dielectric strength results of the test object. It was found that the helium-filled vacuum interrupter maintains its full dielectric strength in significantly larger pressure ranges, while the air-filled vacuum interrupter loses its insulating properties. Thus, it is possible to make vacuum interrupters based on the working medium associated with pure helium, with larger working pressure ratings. Under such conditions, it is easier to maintain the tightness of the device and to limit cut-off currents and overvoltages associated with vacuum switchgear.

Polish power industry is characterized by outdated elements and in poor technical condition. This applies mainly to overhead lines operating at medium and high voltage (MV and HV) levels. Moreover, the Energy Regulatory Office (ERO) requires the Distribution System Operators to supply electricity with specified parameters, ensuring uninterrupted electricity supply to end users. Failure to meet these conditions results in specific financial penalties. In connection with with the above, there is a strong need to upgrade the existing electricity grids using modern equipment. The article presents an innovative, original research position based on the so-called dismountable vacuum chamber, which allows to conduct research on improving the performance of modern switching equipment used in Smart Grid networks. The article also presents the results of the electric strength tests of the inter-contact break in order to confirm the correctness of operation of the described test stand.

The development of power grid infrastructure and increasingly stringent environmental regulations have intensified work, carried out by researchers and electrical equipment manufacturers, to develop innovative gas-insulated, environmentally neutral devices. The emergence of new designs of circuit breakers and disconnectors, in which the resulting electric arc is extinguished in a vacuum environment, requires the development of appropriate techniques for diagnosing the chambers responsible for the dielectric parameters of the device. The following article presents an overview of the directions of development of diagnostic methods for medium-voltage vacuum switching equipment, which can potentially be used to develop a real-time pressure monitoring system that can be applied to vacuum switching equipment used in electrical infrastructure.

W artykule opisano autorski sposób pozwalający na określenie rzeczywistej wartości ciśnienia w próżniowej komorze rozłącznikowej SN podczas wysokonapięciowych badań laboratoryjnych. Konieczność opracowania metody tego typu wynikła z braku możliwości pomiaru ciśnienia bezpośrednio w komorze próżniowej w trakcie badań. Istniało bowiem ryzyko uszkodzenia próżniomierza w wyniku przeskoku elektrycznego. Proponowana metoda polega na pomiarze w warunkach beznapięciowych różnicy ciśnienia pomiędzy zestawem pomp próżniowych, a prototypem komory próżniowej wykonanym dla potrzeb realizacji tej metody. Dzięki temu znając wartość ciśnienia przy pompach oraz mając wyznaczone charakterystyki skalowania układu, w trakcie badań wysokonapięciowych możliwe będzie określenie rzeczywistego ciśnienia wewnątrz badanej rozłącznikowej komory gaszeniowej SN. Przeprowadzono pomiary spadku ciśnienia w kanale pompowym dla powietrza oraz trzech gazów elektroujemnych: helu, argonu oraz neonu, wykorzystywanych w badaniach przez autorów niniejszego artykułu.