Inductive voltage transformers are the basic components of the switchgear equipment or electrical substations. This article presents problems related to their operation. Inductive voltage transformers were exposed to specific working conditions in the form of ferroresonance oscillations with the participation of measurement and protective transformers. The disadvantage and negative significance of the phenomenon contributed to the development of the most convenient elimination methods, which is the main goal and achievement of the publication. The analysis of the proposed solutions were carried out on a theoretical model of a 30 kV power network model created and run in the Electromagnetic Transients Program/Alternative Transients Program (EMTP/ATP). The article presents several results of computer simulations carried out together with their complete characteristics (phase voltage waveforms on the primary side of voltage transformers), which allowed us to indicate the disadvantages and advantages of the solutions developed, and choose the most favorable methods to eliminate nonlinear oscillations. In the article, we present an analysis of all aspects contributing to the solution to the problem. This has permitted an appropriate conclusion to be made indicating the advantage of the method based on the use of a damping resistor in the open delta circuit compared to other solutions. Current solutions are largely based on a product using active variation of the resistance of an open delta attached resistor. The concept in this paper is based on a fixed resistance value, which is a different approach to the problem. By using a switch, the resistor is only connected when a fault occurs. Thanks to this solution, the secondary winding of the open delta is not additionally loaded (despite the very high resistance) at all times during the operation of the power network, as is the case with the available solution.

Static electric fields are used, among others, in technological processes such as electric separation. Electrodynamic separation is a process of separating two or more solid phases of various physical properties by electric field forces. The advantage of electrodynamic separation is possibility of obtaining separation of individual components in dry conditions. This eliminates many operations such as thickening, dewatering, hydrotransportation, additional drying which cause higher energy consumption and higher separation process costs. Efficiency of beneficiation depends on many factors such as: electric properties of feed components, feed particle size distribution, drum rotary speed, electric field intensity in working space of separator, configuration of electrodes or surrounding conditions.The paper presents the working of high-voltage drum separator. The analysis of electric field distribution in separator working space was done. Additionally, distribution of forces acting on particles of dielectric and conductive properties was examined, trajectories of charged particles movement were presented too. The laboratory investigations of electronic wastes were performed in two particle fractions: 0.25–0.5 mm and 0–0.25 mm. It was observed that as a result of selective charging of particles they separate according to surface ability to electrifying what allows to obtain selective separation of components being so-called electronic wastes. The application of electrodynamic drum separator allows to separate such elements as Ti, Cu, Fe, Pb, Sn from plastics occurring in electronic wastes.

E3S Web of Conferences, open access proceedings in environment, energy and earth sciences

E3S Web of Conferences, open access proceedings in environment, energy and earth sciences

W artykule zaprezentowano funkcjonalności oraz możliwości zastosowania platformy narzędziowej SELF. Omówiono cztery zdefiniowane warstwy platformy oraz przedstawiono proces wdrożenia rozwiązania oraz integrację poszczególnych warstw. Przedstawiono...