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The results of development and experimental investigations of the selection of interval boundaries of input and output data method are considered in the paper. The article presents an improved algorithm for obtaining a laws of probability of functional. The experimental part contains examples of finding the full probabilistic characteristics for sums of independent random variables.

The objective of this work is to determine the influence of high-frequency link (HFL) on functioning of phase comparison protection (PCP) through the usage of detailed models that take into account specific features of the PCP and processes in HFL. The article describes the case of the most common variant of the high frequency signal transmission by using a scheme ‘phase-to-ground’. To verify suggested solution the developed mathematical model of HFL has been studied. Presented simulation results confirm the effectiveness of the proposed approach for solving the problem.

Wind power - one the fastest evolving in renewable energy industry. From year to year the share of wind energy in power systems are increasing as well as increasing the size of wind farms. A large-scale wind farms that produce hundreds of megawatts of electricity have a serious impact on the power grid. This paper discusses proposed approaches to modeling wind farms using the Hybrid Real-Time Power System Simulator (HRTSim), to study stability and transient processes in electric power systems.

The dominant trend of the modern energy is the use of generating plants based on renewable energy sources, among which the most common is a wind power plant based on doubly fed induction generator (Type 3 WT). The large-scale introduction of Type 3 WT into the modern power systems significantly changes their dynamic properties. There are problems with ensuring the basic condition of the reliability and the survivability of power systems – the stability. The study and solution of the indicated problems is possible only with the help of the mathematical modeling of a large-scale power systems which is currently being carried out with the help of widespread purely numerical software tools of calculations of modes and processes, which are characterized by various simplifications and limitations. For the properties and capabilities of software tools for studying stability issues, mathematical models of Type 3 WT, the so-called generic models, which also have simplifications and limitations, are adapted. In this article, the reliability of stability calculations of a real power system with Type 3 WT using software tools was evaluated, which allows to identify the influence of the applied simplifications and restrictions with a purely numerical approach on the quality of solving problems of assessing the stability of power systems with Type 3 WT. Also, the studies made it possible to identify the areas of the application of generic models of Type 3 WT as a part of the model of the real dimension power system, at which the greatest and least errors arise, as well as their causes. Such a comprehensive assessment becomes feasible due to the alternative approach proposed in the article, based on the use of a detail benchmark tool model instead of the full-scale data to compare the results of modeling. [ABSTRACT FROM AUTHOR]

Renewable energy sources are being actively penetrated in the global energy sector, with the main growth being achieved by new photovoltaic power stations. At the same time, the influence of photovoltaic power stations on the operation of power systems is known. This is primarily due to the inconstancy of the weather, which leads to a decrease in the output of each specific photovoltaic panel and power station as a whole. To study the effect of partial shading of photovoltaic panels on the parameters of its operation, various models of the current-voltage characteristics of photovoltaic cells are used in the world, while detailed two-diode models show the best results. The use of detailed models allows to get complete information about the processes in a variety of photovoltaic panels of a power station, as well as other elements of it, such as a voltage converter. This makes it possible to assess the impact of these processes on the external power system. However, for detailed modelling of large photovoltaic p ower s tations a s p art o f p ower s ystems, i t i s n ecessary t o u se p owerful s oftware a nd h ardware systems. Such systems include the Hybrid real-time power system simulator. This simulator is a multiprocessor installation that provides a solution to the aggregate model of the power system through the use of three approaches to modelling: digital, analogue and physical. The article presents the results of experimental studies of software and hardware tools for modelling a photovoltaic power station, developed on the basis of a hybrid approach to modelling electric power systems. [ABSTRACT FROM AUTHOR]

This study aims to propose an alternative hybrid approach to model renewable energy sources (RESs), which provide the most reliable results in comparison with the existing simulating tools. Within the framework of this approach, a specialized hybrid processor for modeling converter-interfaced generation (CIG) is developed. This study describes its structure and validation in the test system by comparing the results with commercial modeling tools, and also presents experimental studies of its operation as parts of the practical power system. The results obtained confirm the adequacy of the developed tools. [ABSTRACT FROM AUTHOR]

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Nowadays in the world a lot of attention is paid to the integration of renewable energy sources, especially wind power plants, into existing electric power systems. However, the modern simulation tools usage based on numerical integration for studying and assessment of renewables impact on transient processes in EPS is always associated with different simplifications and limitations. In this regard, the authors suggest the Hybrid Real-Time Power System Simulator (HRTSim) usage for comprehensive and accurate simulation of large-scale EPS with RES. The results of the synthesis of the wind turbine mathematical model as a part of the specialized module for the HRTSim are presented in the paper. The developed means are intended to solve the issue of this hardware-software simulator upgrade for comprehensive and adequate modelling of wind power generation facilities. [ABSTRACT FROM AUTHOR]

The electric power system elements are designed to transmit electricity to consumers. To ensure the transmission, in the design and construction of the power system provide for increased cross-section of lines, throughputs of transformers, cost for other procedures. To find the magnitude of the increase, it is necessary to determine the maximum power flow through the element. This is important for the digital substation operation, where all actions are subordinated to the automation elements, and the ability to control power flows, through the electrical equipment management, has the primary task. This solution is not absolutely effective, since it's not known how much the measures are related to the accident probability. It's needed to know where the maximum power consumption can appear. Therefore, it is necessary to determine in a non-deterministic form how the available power plants power is distributed over the grid to ensure power supply. The main problem is that obtaining the probabilistic characteristics of the parameters by standard statistical methods has no practical solution. In this regard, the method of selection of interval boundaries of input and output data (SIBD) is proposed, and its application for obtaining probabilistic characteristics of electrical quantities and their imbalances. [ABSTRACT FROM AUTHOR]

Electric power systems are becoming more complex. This is due to the widespread use of renewable energy sources (RES) and FACTS devices. At the same time, protection devices for equipment and automation of power systems are becoming subject to influence from new devices. The article pays attention to the study of such influence from the side of RES and FACTS devices on the operation of one of the most important automation systems ensuring the stable operation of the power system - out-of-step protection (OSP). At the first stage of the project, the main reasons for the difficulty of setting up resistance control devices of OSP in networks with FACTS devices and RES were identified, which are related to the fact that the parameters of these devices vary depending on the operation mode, therefore, the zone of the OSP resistance relay should also be changed. Based on the analysis, a new approach to the study of the functioning of OSP in power systems with FACTS devices and RES has been developed. The performed experimental studies confirm the theoretical research. [ABSTRACT FROM AUTHOR]

The introduction of modern technologies significantly changes the modes of operation of electric power systems (EPS) and has an unpredictable impact on the functioning of relay protection devices (RP), in particular distance protection (DP). It is impossible to adequately measured the impact without detailed modelling of both EPS and RP devices. The subject of this research is the development of a detailed mathematical model of digital distance protection (DDP). When designing such a model, both current and voltage measuring transducers, analogue digital relay protection devices, and digital signal processing were taken into account. In this paper, studies are aimed at assessing the correctness of the third stage of the DP using the detailed and simplified model of the DDP. The operation of the compared models is tested on a 39-bus New England system via MATLAB Simulink simulation data, and a comparative assessment is provided. Such detailed DDP mathematical model in combination with an adequate EPS simulator could be used further for solution of different tasks, such as development, design, analysis, testing and setting of RP algorithms. The article presents the results of preliminary studies of the mentioned problem. [ABSTRACT FROM AUTHOR]