GIS-Analysis Of The Ural Power Grid Vulnerability To The Impact Of Sleet And Wind

In this paper, we describe an experiment of complex power grid structure and wind and sleet mapping of territory using two different network indices: standard edge betweenness centrality and new author’s index – electrical grid centrality. Such analysis of the network allows to identify power lines with high load which could be vulnerable elements of the power grid. It is very important for strategic planning of power grids to reduce the risk of accidents by distributing loads across several lines so that they will be able to reserve each other. As a case territory for this research, we took the Ural united power system in Russia which is greatly exposed to different sleet and wind according to the statistics of the power grid operator. The degree of natural hazard consequences could be compensated by the network structure through alternative paths of energy supply or vice versa – increased if they are absent. At the same time, in this paper we consider that power grids have their own features from the graph theory point of view, for example multiple (parallel) edges, branches, different types of vertices. The existing index of edge betweenness centrality does not perfectly cope with them. We compare two indices characterizing power line importance within the system – betweenness centrality and electrical grid centrality and analyze the network structure features together with the spatial distribution of sleet and wind. As a result, we could identify bottlenecks in the study network. According to this study the most vulnerable power lines were detected, for example 500 kV Iriklinskaya CHP – Gazovaya and 500 kV Yuzhnouralskaya CHP-2 – Shagol power lines, that supply big cities such as Chelyabinsk and Orenburg and a bunch of industries around them.

Power management of variable capacitors in electrical grid systems according to the criterion of mini-mum energy loss

The aim is to manage the transmitted reactive power in electrical grids using variable capacitor batteries according to the criterion of minimum energy loss under different annual reactive load schedules and different numbers of variable capacitor sections. The main theoretical relations were obtained by the methods of mathematical modelling and integral calculus using the theory of optimal control. The influence of the power and number of sections in a capacitor battery on energy losses in the grid was estimated using computational experiments. Dependencies for energy losses in a capacitor battery, as well as for reducing energy losses in the grid, were obtained. These expressions are valid for linearized load schedules. It is shown that the dependences of energy losses in a capacitor battery and the reduction of losses in the grid on the section power have inflection points and pass through a maximum. The presence of inflection points is associated with a change in the number of capacitor sections operating throughout the year. The presence of a maximum is explained by the fact that, with an increase in the power of the capacitor battery, its operating time decreases under the complete number of variable sections. It is established that the batteries of static capacitors with two variable sections can reduce energy losses when transmitting reactive power by over 90%. For three- and four-section static capacitors, the loss reduction is close to 100%. The reduction in energy losses increases when approaching maximal levels of annual reactive load. Energy losses in electrical grid systems can be reduced by capacitor batteries with no more than three or four variable sections. In most cases, this can be achieved by two-section capacitor batteries.

A Compressive Compilation of Cyber Security for Internet of Energy (IoE)

Internet of energy (IoE) is the natural evolution of Smart Grid incorporating the paradigm of internet of things (IoT). This complicated environment has a lot of threats and vulnerabilities, so the security challenges are very complex and specialized. This chapter contains a compilation of the main threats, vulnerabilities, and attacks that can occur in the IoE environment and the critical structure of the electrical grid. The objective is to show the best cybersecurity practices that can support maintaining a safe, reliable, and available electrical network complying with the requirements of availability, integrity, and confidentially of the information. The study includes review of countermeasures, standards, and specialized intrusion detection systems, as mechanisms to solve security problems in IoE. Better understanding of security challenges and solutions in the IoE can be the light on future research work for IoE security.

Trust Management Issues for Sensors Security and Privacy in the Smart Grid

Currently, smart grids have changed the world, given the great benefits of these critical infrastructures regarding the customers' satisfaction by offering them the electrical energy that they need for their business. Also, the smart grid aims to solve all the problems encountered in the current electrical grid (outage, lack of renewable energy, an excess in the produced power, etc.) by transmitting and sharing the information in real time between the different entities through the installation of the sensors. This chapter therefore presents the architecture of the smart grid by describing its objectives and advantages. In addition, the microgrids are presented as small electric networks. Then, focusing on the security aspects, an analysis of the different attacks and risks faced in the smart grids and more particularly in the microgrids is presented. After, different techniques and suitable security solutions are detailed to protect and secure the various elements of the smart grids and microgrids.

Techno-economic analysis of hydrogen production from PV plants

Hydrogen production through electrolysis from renewable sources is expected to play an important role to achieve the reduction targets of carbon dioxide emissions set for the next decades. Electrolysers can use the renewable energy surplus to produce green hydrogen and contribute to making the electrical grid more stable. Hydrogen can be used as medium-long term energy storage, converted into other fuels, or used as feedstock in industry thus contributing to decarbonise hard-to-abate-sectors. However, due to the intermittent and variable nature of solar and wind power, the direct coupling of electrolysers with renewables may lead to high production fluctuations and frequent shutdowns. As a consequence, accelerated electrolyser degradation and safety issues related to low load operation may arise. In this study, simulations of hydrogen production with an electrolyser fed by a PV system are performed in Matlab for a reference year. The effect of PV power fluctuations on the electrolyser operation and production is investigated. The impact of the electrolyser size for a fixed nominal power of the PV plant is also analysed from both energetic and economic points of view.

Elastic Energy Management Algorithm Using IoT Technology for Devices with Smart Appliance Functionality for Applications in Smart-Grid

Currently, ensuring the correct functioning of the electrical grid is an important issue in terms of maintaining the normative voltage parameters and local line overloads. The unpredictability of Renewable Energy Sources (RES), the occurrence of the phenomenon of peak demand, as well as exceeding the voltage level above the nominal values in a smart grid makes it justifiable to conduct further research in this field. The article presents the results of simulation tests and experimental laboratory tests of an electricity management system in order to reduce excessively high grid load or reduce excessively high grid voltage values resulting from increased production of prosumer RES. The research is based on the Elastic Energy Management (EEM) algorithm for smart appliances (SA) using IoT (Internet of Things) technology. The data for the algorithm was obtained from a message broker that implements the Message Queue Telemetry Transport (MQTT) protocol. The complexity of selecting power settings for SA in the EEM algorithm required the use of a solution that is applied to the NP difficult problem class. For this purpose, the Greedy Randomized Adaptive Search Procedure (GRASP) was used in the EEM algorithm. The presented results of the simulation and experiment confirmed the possibility of regulating the network voltage by the Elastic Energy Management algorithm in the event of voltage fluctuations related to excessive load or local generation.

Energy Management Systems for Optimal Operation of Electrical Micro/Nanogrids

Energy management systems (EMSs) have been introduced in electrical power systems to optimize operations of the electrical grid infrastructure and to provide support to the grid operator in terms of optimized decisions [...]

Power Management Analysis of a Photovoltaic and Battery Energy Storage-Based Smart Electrical Car Park Providing Ancillary Grid Services

Future car parks will require significant power to support electric vehicle (EV) charging as there will be both an increase in the penetration of EVs and a higher demand for charging power as battery packs increase in capacity. The effective management of the charging and local battery storage can be installed to help prevent excessive increases in electrical feeder capacity; however, it is inevitable that car parks will attain significant power capability in the future. There is therefore an opportunity for car park owners to utilise this and generate additional revenue by providing frequency response services to the electrical grid. This paper describes the modelling of a car park that utilises photovoltaic power generation, battery storage, and EV charging management strategies to provide a grid frequency response service. The analysis using simulated car park data shows that it can provide a high availability in terms of service but it is dependent on the capacity of the installed generation and storage.