This paper focuses on the determination of the characteristics of refusals in low voltage electrical distribution systems. In order to solve this problem, the phenomena of occurrence of refusals in low-voltage electrical distribution systems, conditioned by different influencing factors, processed and mathematically modelled. The main results of the research consist in establishing the static characteristics of the refusals, the mathematical models that determine the occurrence of the cause phenomena and the parameters that characterize the distributions of the refusals, depending on the occurrence per system, depending on the occurrence per season, depending of interruptions duration and the number of affected consumers. The significance of the results obtained consists in solving a number of problems faced by the operating services of electrical distribution systems, concerning the assurance of reliability of operation, providing the possibility of forecasting and preventing the occurrence of the phenomena of occurrence of refusals, which enable the justified planning of prophylactic measures and ensuring the reliability level.

The paper described the variant of Interphase Power Controller (IPC) conjugated with power electronic converter. This form of IPC provides more independent control both active and reactive power flows. Schematic configuration of device is described. The control strategy for the steady state operation to maintain the required power characteristic of IPC is outlined. The preliminary results confirm the expected behavior of device.

This publication provides a brief overview of the results of research work in the field of developing alternative methods, schemes, and algorithms of synchronous multi-zone modulation of signals of inverters of power conversion systems with reduced switching frequency of power switches. In particular, in the mentioned researches, the basic strategies, schemes, and algorithms of synchronous multi-zone modulation have been fur-ther developed, modernized, modified, and disseminated in relation to new promising topologies of power conversion systems, including: two-inverter-based electric drives with open windings of electrical motor; drive systems based on electric motor with two stator windings; dual three-phase electric drives of symmetrical and asymmetric type; five-phase power conversion systems, powerful six-phase systems based on four inverters, and two-inverter-based and three-inverter-based photovoltaic installations with multi-winding transformer. It is shown that the developed schemes and algorithms of synchronous space-vector modulation applied for control of inverter-based systems provide continuous synchronization and symmetry of the basic voltage waveforms of systems during the whole control range. It provides minimization of even harmonics and undesirable subhar-monics (of the fundamental frequency) in spectra of the basic voltages of systems, leading to reducing of losses in systems and to increasing of its efficiency. Based on a comparative analysis of the integral spectral character-istics of the phase and line voltages of the systems, recommendations are formulated for the rational choice of schemes and algorithms of synchronous modulation for the relevant installations, depending on the modes of their operation.

The development of power engineering assumes the increasing flexibility of power networks through the use of various kinds of FACTS, controlled by means of power electronics and being elements of the Smart Grid. These kinds of devices can be attributed to controllers such as UPFS and „Sen” Transformer (ST), which provide regulation of voltage and power flows in networks. Due to the relevance of this topic, technical solutions are proposed that perform similar functions, which implies the need for a comparative analysis of such developments in order to optimize energy characteristics of the equipment. The scope of the paper is to develop and study a regulating transformer which belongs to the „Sen” family, but possessing the extended range and higher control accuracy. Carrying out research, mode parameters of the device were treated, as well as typical power was determined.

The electric power industry development mean increases the electric grids flexibility through the use of various devices type (FACTS) controlled by means of power electronics and being an element of the Smart Grid. This type of device includes a phaseshifting transformer (PST), which redistributes power flows in the branches of electrical networks. In connection with the relevance of this topic, new technical solutions appear that implement similar functions, which entails the need for a comparative analysis of such developments in order to optimize the energy characteristics of this kind of equipment. The aim of the work is to develop schematic version of the PST made according to the "star" scheme and analyze its operation in typical modes. During the study, the energy characteristics of the device were determined. The possibility of reducing the typical power of the phase-shifting device due to the use of capacitive compensation is analyzed.

The aim of this study is to examine the feasibility of establishing urban monitoring systems to support the energy transition. To achieve this aim, the following tasks were addressed: analyzing the limitations of traditional synchronous Advanced Metering Infrastructure (AMI) systems; demonstrating the advantages of shifting to asynchronous systems—which utilize a unified technology and set of rules to collect granular data not only on resource consumption but also on weather conditions and indoor/outdoor air pollution, with adjustable granularity for each parameter; and identifying the initial step in deploying urban monitoring systems—the international ASMI pilot project—while outlining its goals, objectives, and expected outcomes. Key results include moving away from complex "smart meters" in favor of extremely simple, low-cost sensors; standardizing data transmission protocols across all monitored parameters; and reducing the costs associated with establishing and operating the monitoring system. The significance of these results lies in the fact that lower costs and enhanced data value pave the way for a new market—a market for urban resource consumption and environmental data—thereby attracting private-sector investment and laying the groundwork for future research involving artificial intelligence, the directions of which are outlined in the article.