This article presents the issue of the impact of the operation of prosumer installations on the operation of the distribution network. The emergence of a very large number of distributed generation units in electric distribution networks (in particular, photovoltaic installations in low-voltage grids) can be associated with both positive and negative consequences. Positive consequences can include, among others, the environmental aspect of electricity generation. Negative consequences, on the other hand, can include technical problems of power grid operation, manifested, for example, in changes that can be observed in steady states, in the values of such parameters of grid operation as voltage level, values of branch currents, or power and energy losses. The issue discussed will be illustrated by a calculation example considering, among other things, the size and location of the prosumer installation.

The paper addresses the problem of placement of sectionalizing switches in medium voltage distribution networks. Proper placement of sectionalizing switches is one of the elements leading to higher power networks reliability. The methods of optimal allocation of such switches in a MV distribution network are presented in the paper. SAIDI was used as a criterion for the sectionalizing switches placement. For selecting optimum placements, three methods were used: brute force method, evolutionary algorithm and heuristic algorithm. The calculations were performed for a real MV network.

This paper presents the issues related to aging studies of electrical insulation in winding wires, which are widely used in electrical machines. Insulating materials in electrical machines are subjected to various stress factors, particularly electrical stress. The proper design of such insulation systems requires an understanding of the behavior of individual system components under specific operating conditions. This knowledge enables the optimization of insulation design, which can contribute to extending the operational lifespan of electrical machines. In this study, the results of experimental investigations on twisted-pair winding wires with different geometric dimensions, subjected to electrical stress (a square voltage waveform in the kilohertz frequency range) under different pressure conditions, are presented. The experimental research is supplemented by simulation-based calculations of the electric field intensity in the examined twisted-pair winding wire samples.