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The paper presents the results of voltage and current measurements performed in electrical drive system of CNC machines. The tests were made for different operation states of devices. We analysed the influence of nonlinear devices for current and voltage waveforms. The measurement results are shown as current and voltage waveforms, and charts present harmonics and their participation in waveforms...
The paper considers some analytical expressions for magnetization curves of chosen soft magnetic steels. The limiting cases of the considered expressions in the low and high field regions are shown to correspond to well-known Rayleigh and law of approach to saturation (LAS) formulas.
The aim of this article is to analyze the investment and operational costs (the costs discounted) of the medium-voltage overhead lines with covered conductors as a function of applied overvoltage protection. On the basis of a technical-economic comparative analysis of the most popular and prospective protection measures, two surge protection systems (whose use is economically justified) will be further...
The selection of reactive power compensation and higher harmonic filtration method for an exemplary industrial plant was presented in the paper. Based on measurements carried out on the real object, four solutions were proposed i.e. a passive filter, a modified passive filter and an active filter without and with a higher harmonic filter. For the proposed solutions the proper simulations were performed...
In the paper the results of experimental research on residual current protective devices with different design of the release system are presented. The application of a summing transformer and a power adjustment system in the secondary circuit affects the release frequency range. In the circuits of installations, where due to the specific features of the supplied devices, there are some current deformations...
The corrosion process in devices and equipment of switchgears strongly depends on environmental parameters. In some cases, degradation of copper conductors and other insecure elements is impermissible intense and provides the increase of failure and exploitation costs of such devices. In the paper, an author's system for measurement and registration of chosen environmental parameters is presented...
The IEC 60243 standard is the most common method of measuring the dielectric strength of dry insulating materials, but the nature of the setup leads to PD ignition at the triple point around the perimeter of the HV electrode. In this article the electric field distributions simulated for various test electrode arrangements are compared. The test electrode size and shape is taken into account, as well...
The article describes a simulation study showing the impact of the superconducting fault current limiter (SFCL) on the values of the short-circuit current and the voltage at the substation busbar for different short-circuit locations. On this basis the required changes in settings of preventive protections have been studied and, moreover, a positive impact of the SFCL on the distributed network during...
This paper summarizes authors' experience with the operation of both versions of autonomous humanoid robot Pepper. The robot's construction, as well as its capabilities and limitations are discussed and compared to the NAO robot. Practical background of working with Pepper robots and several years of experience with NAO, result in specific know-how, which the authors would like to share in this article...
The paper presents an assessment of the electric energy quality in a industrial plant. The assessment was based on the PN-EN 50160: 2010 - Characteristics of supplied voltage in public power networks. The analysis was based on actual measurements made by power quality recorder Fluke 1760. In the analysis the particular attention was made to the flicker. On the basis of flicker have been identified...
This paper presents the analysis of bidirectional Transient Voltage Suppressor (TVS) application for limitation of the electric arc energy in a low voltage circuit. The study employs both simulations and laboratory experiments, which were conducted to present inductive current breaking procedure with use of a standard switch and a switch with passive arc suppressor connected in parallel. EMTP-ATP...
The paper presents the method of digital modelling of process of switching on by vacuum switch in capacitive circuits. Currently, there are few descriptions of vacuum switch models used for capacitive circuits switching on. More often researchers focus on vacuum switch models used for switching of the circuits (also previous works of the Authors) and even more often models used for switching of the...
The paper focuses on the effect of frequency variations on the shape of modeled hysteresis loops. The concept relies on a modification of value of single parameter related to coercive field strength. The considered description is the GRUCAD model. It is a low-dimensional description based on a ordinary differential equation and some auxiliary nonlinear relationships.
TETRA-PAK® packages are composed with cellulose and a composite material composed with aluminum foil mutually covered by polyethylene. Recycling of an aluminum layer is often realized in thermal depolymerization process. In many cases, indirect heating methods are in use. According to this fact, total efficiencies of the process are at low values. In this paper possibilities of using the induction...
The article contains an overview of the type testing carried out for face shields used in Live Workings to protect against the thermal effects of electric arc flash. The main part of the article describes a workstation established for helmet resistance testing with an integrated face shield protecting against the thermal impact of an electric arc.
The subject of this paper is to present modern technological solutions in terms of architectural generation/processing, and transmission and distribution of electricity. It concerns both “classic” civil aircraft (Airbus, Boeing) and aircraft compatible with the trend of the aircraft fully/partially electric MEA/AEA (“More/All Electric Aircraft”), as well as military aircraft (Lockheed Martin) of “conventional”...
The paper proposes the circuit model of 10 kVA superconducting transformer implemented in PSpice. The model of second generation superconducting tape allow for the simulation of smooth transition of the yttrium superconducting layer into resistive state. Dependence between the electric field intensity and the current density is described by Rhyner's power-law. A modified Jiles-Atherton equation has...
The subject of this paper is to make an analysis of advanced autonomous power systems (EPS, PES). This in particular includes to simulate the operation of a model of the Auxiliary Power Unit (APU) in the field of the power supply system EPS (Electric Power System). It ensures the proper operation of basic equipment and systems powered by electricity on board of a modern aircraft compatible with the...
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