The management of the power transformer population is a complex process, as the grid companies operate thousands of devices. For this issue, the health index method can be applied to facilitate asset management. The algorithm can be used not only in the technical assessment of the individual units, but also to determine the relationships within the whole population. In this paper, the presented health index method consists of periodic oil diagnostics, including the physicochemical properties, dissolved gas analysis, and furfural content, and further assessment in terms of the criticality of the device to determine the technical condition. The algorithm was specifically designed to reflect even the smallest changes of the input parameters in the final score. The performance of the health index was tested on 620 oil analyses from 220 transformers divided into four subpopulations based on the service conditions. The results have proven to be largely dependent on the criticality level and the operating conditions of the device. The analysis of the study group has shown the influence of corrective maintenance on the mean value of the health index score.

This paper presents the dielectric response of the insulation of bushings as an effect of the simulated long-term aging process. The experiment was conducted under a condition of a high temperature difference between the current circuit and the cover. The dielectric response was measured with the FDS (Frequency Dielectric Spectroscopy) and the SVM (Step Voltage Measurement) methods. The research has shown the correlation between the aging time and some parameters obtained with the FDS and SVM analysis.

This study presents the results of research on energy self-sufficiency, safety and production reliability in a salmonids fish farm. For the needs of the breeding facility under construction in the Recirculating Aquaculture System, energy requirement analyses were carried out and guidelines collected for the implementation of innovative solutions, which ensure the security and continuity of energy supplies and the plant’s energy self-sufficiency. This research included the development of solutions for the reliability of power supply and ensuring the continuity of operation of devices that are key to the fish farming process, i.e., lighting and pumps. In terms of ensuring the necessary amounts of energy, the possibility to diversify electricity sources was analysed, taking into account the possibility of self-production, including primarily from a photovoltaic power plant and from average power wind farms. The profitability of using energy storage was also examined. Recommendations and a list of energy balances for selected cases of potential power sources are presented.

Wydawnictwo SIGMA-NOT wydaje czasopisma fachowe informujące swoich czytelników o najnowszych osiągnięciach naukowych i nowoczesnych rozwiązaniach technicznych w Polsce i na świecie, popularyzuje problemy techniczne oraz poszerza wiedzę i kulturę techniczną.