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International audience; An experimental study of the inception of the first-mode negative streamer at liquid/solid interfaces is presented in this article. The study is performed with a point-plane configuration under square high voltage pulses. The electrode configuration is immersed in mineral oil and the liquid/solid interface is assembled in contact with the point electrode or in its vicinity. Four polymers and two impregnated papers have been tested as solids of the liquid/solid interface. Thus, it is possible to compare the influence of different parameter of the solid and the interface on the streamer inception. For example: Permittivity, solid surface roughness, chemical composition, etc. It has been observed that streamer inception voltages at interfaces with solids of higher permittivity to that of the mineral oil are statistically similar. Additionally, streamer inception voltages of streamer initiated free in the oil (no liquid/solid interface) are similar to that of the inception voltage of cases with solids with high permittivity. In contrast, the inception voltage of streamers initiated at permittivity matched interfaces are shown to be highest of the cases. The streamer inception voltage is also studied for different distances between the liquid/solid interface and the point electrode with a permittivity matched interface. The results show a dependency of the inception voltage and the distance between the point electrode and the interface. Finally, an analysis of the observation is performed to show that the Townsend-Meek criterion cannot predict the obtained results.

The conventional structure of operating transmission and distribution systems is currently experiencing new challenges in maintaining the system operability with the significant changes such renewable energy sources inclusion, technology development, infrastructure revolution, and services provision. A futuristic operation management paradigm at the high level of interaction between Transmission System Operators (TSOs) and Distribution System Operators (DSOs) is presented that supports the usage of flexibility services to simplify the congestion management, and ancillary services procurement by involving the DSO actively in the DSO-TSO boundaries and the downstream network. The architecture considers new actors such as Distributed Services Aggregator, Prosumers, and Services Market Operators. A comparison between the typical grid structure (including the short-term smart grid requirements) and the proposed one is presented considering different actors and interactions involved in the operation management of the grid. The opportunities and challenges of the proposed architecture are discussed. ispartof: IET Energy Systems Integration vol:2021 issue:1 pages:1-12 status: published