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The paper considers the possibilities of increasing the flexibility of power distribution systems by real-time load management. The principles of the implementation of special automatic systems for this purpose are proposed. These systems enable some loads of specific consumers of the power distribution system switched to islanded operation to "shift" from the daily maximum to the minimum, which makes some generators available to connect certain essential consumers disconnected earlier by under-frequency load shedding system to the power system. The approach under consideration is illustrated by a power system with distributed generation. [ABSTRACT FROM AUTHOR]

Global electricity companies have embarked on a transition to digital microprocessor devices. Digitalization penetrates every aspect of power industry, whether it is power generation, transmission or distribution. Being the most widespread, the distribution electrical networks are nevertheless the least digitalized. Some issues about them are still insufficiently studied. These are the collection of necessary information, adaptation methods, and the effect of the unrecognizability of some short circuits. This can be explained by improper placement of devices, which causes lack of data, which, in turn, leads to the failure of relay protection and emergency control systems of distribution electrical networks to provide selectivity. The paper proposes algorithms for placing measuring devices so that the information will be collected properly. Placement of the devices will allow adjusting the operating parameters of the relay protection and emergency control systems depending on changes in external weather conditions and load fluctuations in the network. We propose a technique for control of distribution network, taking into account the type of damage in case of emergency in real time, and a technique for placement of measuring devices and creation of an information communication network. [ABSTRACT FROM AUTHOR]

The guidelines for the design of rural and urban power supply systems do not consider the issues of reactive power compensation and reduction in additional losses due to unbalanced and non-sinusoidal conditions. At the same time, today's rural power consumers have a great number of non-linear loads in their residential premises. Moreover, the unbalanced phase currents and voltages are an established fact. The paper aims to demonstrate the extent to which power quality and losses vary in real rural 0.38 kV networks. To this end, the objectives were posed to study the operation of two facilities: 1- switchgear at the cottage (with an installed capacity of 15 kW); 2- switchgear at the communal entrance hallway for 60 apartments in an apartment building (with an installed capacity of 75 kW). [ABSTRACT FROM AUTHOR]

This paper describes how flexibility of medium voltage systems can be used for operation of high voltage systems. This is explained using the example of a congestion management system for high voltage networks developed in the research project IDEAL. First, it is explained to what extent flexibility is required for high voltage system operation. After that, the entire congestion management system with flexibility of medium voltage systems is presented. Then, methodology for observability analysis, state estimation and determination of flexibility potential is shown. Finally, the implementation of the methodology in two real medium voltage systems is described. [ABSTRACT FROM AUTHOR]

This Research Approach shows how to use flexibilities of E-Mobility in planning and operation of electric grid with grid-supporting charging infrastructure. In the first part, we show how to deal with controlled and uncontrolled charging behavior during the planning of electrical grid. Therefore we show a tool for generating load curves and simultaneity factors and an example, how to use them for grid planning. The second part shows the concept of grid-supporting charging infrastructure, a simulation of the main functions and a feasible implementation in the Smart Grid Technology Lab of TU Dortmund University. [ABSTRACT FROM AUTHOR]

The paper discusses the problem of parallel operation of wind and solar power plants with the power system associated with the influence of power fluctuations on the power quality and stability. A brief assessment of the prospects for the commissioning of the wind and solar power plants in Russia and a description of the associated negative impacts on the power system is given. A methodology for assessing the possible energy production of wind and solar power plants using raw data from weather stations is presented. Based on the methodology, an assessment of some regions of Russia in relation to the variability of wind speed and cloudiness is made. The wind power duration curves are given. An analysis of possible deviations of solar power under the influence of cloudiness is carried out. The effect of geographical aggregation of wind or solar power output to increase the guaranteed power generation and reduce the negative impact on the stability of the energy system is shown. [ABSTRACT FROM AUTHOR]

This paper deals with actively studied terms "flexibility" and "resiliency" of electric power systems (EPS). Definitions and content of these new fundamental EPS properties are analysed. Objective trends in development of EPS with regard to these properties are discussed. Possible measures for improving flexibility and resiliency of EPS are suggested. [ABSTRACT FROM AUTHOR]

The state of the art of transient stability and steady-state (small signal) stability in power grids are reviewed. Transient stability concepts are illustrated with simple examples; in particular, we consider two machine learning-based methods for computing region of attraction: ROA produced by Neural Network Lyapunov Function; estimation of the ROA of IEEE 39-bus system using Gaussian process and Converse Lyapunov function. We discuss steady state stability in power systems, and using Prony's modal analysis for evaluating small signal stability for the 7 Bus Test system and real French power system. [ABSTRACT FROM AUTHOR]

The problem of optimally activating the flexible energy sources (short- and long-term storage capacities) of electricity microgrid is formulated as a sequential decision making problem under uncertainty where, at every time-step, the uncertainty comes from the lack of knowledge about future electricity consumption and weather dependent PV production. This paper proposes to address this problem using deep reinforcement learning. To this purpose, a specific deep learning architecture has been used in order to extract knowledge from past consumption and production time series as well as any available forecasts. The approach is empirically illustrated in the case of off-grid microgrids located in Belgium and Russia. [ABSTRACT FROM AUTHOR]

The power system experiences many changes, which are leading to new challenges. The electric energy will no longer be generated only by large power plants, but rather by numerous decentralized energy resources that are primarily installed in distribution grids. In particular, power system restoration processes after a blackout will face new challenges. However, new opportunities by the widespread use of renewable energy resources arise. In this paper, the black start capability of a real distribution grid in Germany, operated by SWW Wunsiedel, will be investigated, as it has a high share of decentralised energy resources and a BESS with black start capability. For this purpose, the medium voltage level of the distribution grid is investigated with static load flow simulations to evaluate the best black start strategy. The driving forces of this black start concept are an 8 MW BESS unit and a 13.5 MW CHP plant. [ABSTRACT FROM AUTHOR]

The paper presents a method developed for detecting rough errors in the measurements related to batteries in the part of electric power system that is characterised by low data redundancy. Since batteries either produce or consume power, not all methods of bad data detection can be used to detect erroneous measurements of the active power of the battery in the case of low measurement redundancy. Because of different values of the active power that a battery may produce or consume at several snapshots in row, dynamic algorithms cannot be used. In this study, a new method of bad data detection is developed. The method is based on the battery control strategy analysis. [ABSTRACT FROM AUTHOR]

The article discusses the application possibilities of machine learning methods (artificial neural networks (ANN) and genetic algorithms (GA) to form management actions when applying the concept of situational management for intelligent support of strategic decision-making on the development of energy. At the first stage, the application of ANN to classify extreme situations in the energy sector, to select the most effective management actions (preventive measures) in order to prevent a critical situation from developing into an emergency. Genetic algorithms are proposed to be used to determine the weighting coefficients for training ANN. An algorithm for constructing a classifier based on a neural network and a demonstration task using data on generation and consumption of the United Electric Power System of Siberia are presented. [ABSTRACT FROM AUTHOR]

The problems of energy sector digital transformation in Russia are considered. The problem of insufficient use of the results available in scientific organizations of the energy profile is highlighted. Attention is drawn to the need for intelligent support for the justification and adoption of strategic decisions on the development of technological infrastructure (digital transformation of energy sector). An approach is proposed to solve the problem of integration of software, information support and intelligent information technologies developed at Melentiev Energy Systems Institute of SB RAS. The architecture of a multi-agent intelligent environment providing this integration, and a multi-agent methodological approach to its development are considered. [ABSTRACT FROM AUTHOR]

The question of whether a process variable transmitted from a device in the field to a power system control center is trustworthy is of high importance nowadays. Traditional bad data detection schemes have their limits in cases of elaborated cyberattacks and cascading failures in a system of systems such as a digitalized power system. This paper proposes a trust model designed for power system network assessment (PSNA). Different to other domains, where trust models already exist (e.g., OC-Trust for organic computing systems), the environment for PSNA is more centralized, and the focus lies on other facets than in organic computing due to the nature of the environment. Therefore, OC-Trust is tailored by categorizing its facets regarding their relevance for PSNA on the one hand. On the other hand, the trust model is extended to realize context-sensitive intersections of trust values. Furthermore, an example of an instantiation of the resulting PSNA-Trust model is given. Two security metrics and one credibility metric based on literature are presented as well as an equation for a context-sensitive intersection. [ABSTRACT FROM AUTHOR]

A digital substation is an example of a cyber-physical system that is a sophisticated system consisting of two closely interrelated subsystems: physical (technological) and information-communication ones. Sophistication and vulnerability of an information-communication subsystem that performs functions of management becomes comparable to those of a physical subsystem. In the latest years the studies have been focused on the problems of cyber attacks against information-communication subsystems as potential external disturbances of present-day cyber-physical systems. Resilience is ability of an informational system to survive in the conditions of continuous cyber attacks. The proposed here approach to assessment of digital substation resilience using an event tree can serve as expert's assistance in ensuring the digital substation resilience. [ABSTRACT FROM AUTHOR]

When planning and managing the present-day and future transformed electric power systems (EPS), such comparatively new properties as flexibility and cyber resilience shall be taken into account along with EPS conventional properties, such as Reliability, Security, Survivability, and Vulnerability. Large-scale introduction of renewable energy sources notably lowers the EPS flexibility. Installation of Energy Storages allows compensation of power production imbalance occurred when using renewable energy sources, which makes the energy system more robust, but lowers its cyber security. The paper considers the main performances and models of Energy Storages, their impact on flexibility and cyber security of electric networks; it also presents the technique for quantifying the flexibility of a network with Energy Storages, and identifies most promising directions of studies in this area. [ABSTRACT FROM AUTHOR]

Using a simple test example, this paper demonstrates that a weakly damped eigen-oscillation of an electric power system can lead to a loss of stability in the presence of its resonance with forcing oscillation. Such resonant interactions can risk the power system security, as confirmed by recent events in the Western American and Nordic power systems. Conventional eigenvalue analysis cannot detect the observed instability due to its non-linear nature. We show that the critical condition for the appearance of this type of instability can be the value of the perturbation energy accumulated in the system over time. To quantify the risk of stability loss, we examine the model of forcing oscillations and the resonance response of power system in a linear approximation and compare it with the simulation results for the two-area Kundur test system. [ABSTRACT FROM AUTHOR]

The integration of the voltage-source converter based high voltage direct current (VSC-HVDC) system makes the set-point of its active power adaptive to the changes in the power flow, and contributes to the curative congestion management. To further exploit the dynamic behavior of a hybrid AC/DC power system in curative congestion management scenarios, this paper investigates a novel control scheme for voltage angle droop controlled HVDC (VAD-HVDC) systems. The proposed scheme to alleviate the circuit overload is estimated firstly by calculating the severity index when the power flow changes under N-1 situations. Then the voltage angle controlled HVDC system is applied on the modified IEEE 39-bus 10-machine test power system for the time-domain simulation. The dynamic behavior in the HVDC station validates that the VAD control can stabilize the DC voltage and possess a good ability against interference. In addition, the dynamic characteristics analysis on the AC transmission lines proves that the hybrid AC/DC system integrated with the VAD controlled HVDC system are in possession of good stability after the N-1 contingency event. The VAD controller employed in the HVDC system is capable of effective congestion management to mitigate the critical loadings on the transmission lines. [ABSTRACT FROM AUTHOR]

The subsystem for optimal control of voltage and reactive power of EPS is developed. The proposed solution uses state of art methods for state estimation, forecasting and dynamic optimization. A new architecture of an artificial neural network is proposed – a neuro-analytical network. Algorithms are proposed that allow reliable combination of classical automatic control methods and methods using machine learning. The proposed methodology is designed for use in a real power system for automatic voltage control. [ABSTRACT FROM AUTHOR]

Modern cities and industrial centers boast a developed energy infrastructure including fuel, electric, heating, and cooling systems. The integration of many separate system into a single technological complex can provide new functional capabilities, the application of more advanced technologies for operation, and the establishment of integrated energy systems. Such systems have a multidimensional structure of functional features and properties of development. The control of integrated energy systems with load-controlled consumers represents an urgent and a rather challenging task. The paper is concerned with an approach to short-term control of integrated energy systems with load-controlled consumers. Planning the daily electricity and heat loads is performed for an integrated energy system, including energy storage systems and electric water heaters, electrical shiftable loads of individual consumers as well as power generation by additional electricity and heat sources (PV systems, wind turbines, heat pumps). The optimal daily profiles are obtained based on the initial profiles of electricity and heat loads, photovoltaic generation and optimal profiles of using electricity and heat storage systems and shiftable load. Optimal daily electricity and heat load profiles differ greatly from the initial ones, which provides a reduction in the energy costs for the consumer. [ABSTRACT FROM AUTHOR]