Grzegorz Wisniewski

This article presents and discusses the structure, principle of operation, and operational properties of a newly developed interference level detector (ILD) designed to measure conducted supraharmonic disturbances (1–150 kHz) in the power grid and to assess the effectiveness of narrow-band Power Line Communication (PLC) transmission, especially in the PRIME technology. The usability assessment was made on the basis of the validation and the results of tests carried out in a low-voltage network with non-linear loads. Appropriate practical conclusions were then formulated.

Knowledge of the conducted emissions in the frequency range 2–150 kHz contains some gaps related to the impact of the harmonics in the supply voltage on the nature of these emissions. It can be noticed that the conducted emissions from non-sinusoidal power supplies have not been studied sufficiently, and that the impact of this distortion may be greater than the generally known results of emission tests carried out under standardized test conditions. This paper is aimed at investigating experimental cases of the influence of supply voltage waveform distortion on non-intentional emission in the range 2–150 kHz and the efficiency of power line communication based on selected PRIME (PoweRline Intelligent Metering Evolution) power line communication (PLC) technology. A series of experimental laboratory studies were investigated, representing the operation of the investigated PLC system with different types of end-user equipment (LED—Light Emitting Diode, CFL—Compact Fluorescent Lamp, induction motor with frequency converter) working under a distorted supply voltage condition obtained by the programmable power supply for different scenarios of the admissible harmonics contribution in the range 0–2 kHz. The scenarios included limits defined in standards EN 50160 and IEC 61000-4-13. The researchers used spectral analysis with a notation to emission limits, compatibility levels, and mains signalling, as well as statistics of the PLC communication. The obtained results provide important conclusions, which may be applied both in the development of the design of the appliances in question and the higher frequency emission testing methods.

Application of a high-efficiency voice communication systems based on broadband over power line-power line communication (BPL-PLC) technology in medium voltage networks, including hazardous areas (like the oil and mining industry), as a redundant mean of wired communication (apart from traditional fiber optics and electrical wires) can be beneficial. Due to the possibility of utilizing existing electrical infrastructure, it can significantly reduce deployment costs. Additionally, it can be applied under difficult conditions, thanks to battery-powered devices. During an emergency situation (e.g., after coal dust explosion), the medium voltage cables are resistant to mechanical damage, providing a potentially life-saving communication link between the supervisor, rescue team, paramedics, and the trapped personnel. The assessment of such a system requires a comprehensive and accurate examination, including a number of factors. Therefore, various models were tested, considering: different transmission paths and types of coupling (inductive and capacitive), as well as various lengths of transmitted data packets. Next, a subjective quality evaluation study was carried out, considering speech signals from a number of languages (English, German, and Polish). Based on the obtained results, including both simulations and measurements, appropriate practical conclusions were formulated. Results confirmed the applicability of BPL-PLC technology as an efficient voice communication system for the oil and mining industry.

Wydawnictwo SIGMA-NOT wydaje czasopisma fachowe informuj?ce swoich czytelnik?w o najnowszych osi?gni?ciach naukowych i nowoczesnych rozwi?zaniach technicznych w Polsce i na ?wiecie, popularyzuje problemy techniczne oraz poszerza wiedz? i kultur? techniczn?.

The article presents the structure, principle of operation and measurement properties of the developed control system intended for e-management of detection and measurement of disturbances in the low-frequency bandwidth of the PLC (3 kHz-148 kHz). As a detector, Rogowski’s coil made in high-density printed technology (PCB HDI) was used. The results of testing the parameters of both particular components and the completed system in transient as well as in steady state are presented. Based on the obtained measurement results, appropriate practical conclusions are formulated.

Effective performance of active power filters when combined with static compensation units operated in the power system with nonlinear loads has been considered in this article. The paper presents therefore, results of selected experimental and simulation studies to specify the conditions and the risks of such cooperation. On the basis of the results obtained, respective conclusions and recommendations for practice are formulated.

The aim of the article was to consider the results of experimental investigations of the switching arc to glow transformation and their comparison to the theoretical considerations performed previously. On this basis, it was possible to draw practical conclusions regarding the control of this effect in low voltage (<;250V) inductive circuits of an energy not over 10J. The theoretical evaluation of the arc instability conditions was used as a key factor.

The article discusses the basic principles of BPL-PLC transmission paying attention to the limitations of its efficiency in medium voltage cable networks. A way of performing appropriate tests concerning the effectiveness of using the right way of the modem coupling with the cable line has been described. Based on the results obtained, respective practical conclusions have been formulated.

The article describes regulations specifying the requirements for the quality of electricity supplied to households and other low voltage recipients. The requirements were characterized in detail, and then the measurements of electricity quality among selected individual recipients were carried out. The analysis of measurements and conclusions have been presented in the summary.

The paper presents a stand for testing one-second short-circuit currents of medium voltage power cables. The operation of the stand was illustrated with the results of short-circuit currents of Al cables with cross-sections (main wire/return wire) of 70/36, 120/40 and 240/48. Time changes of short-circuit current values recorded during the test and its influence on deformation of the return veins were shown.