Security Of Electricity Supply Research Articles

Development and Integration of Photovoltaic Complex Systems in Optoelectronic and Power Applications

This thesis presented innovative dimensioning and implementation of autonomous photovoltaic systems is primarily aimed at ensuring the energy independence of the receiver (consumer), the security of electricity supply and the adaptation to meteorological conditions in the area where they are located. The PV system components are based on literature, but their characterization was possible by implementing the components / system in the MATLAB / Simulink work environment to determine the behavior and performance of the analyzed system for different applications. We also analyzed the interdependence of the subsystems and how they affect the efficiency of the PV system. The main contribution of this paper is based on MPPT method and FLC controller used in order to optimize the behavior of applied PV systems

Альтернативна модель конкурентного ринку електроенергії України (частина 2)

The development of a competitive electric energy commodity market in Ukraine does not guarantee the creation of the necessary conditions for the security of electricity supply and the adequacy in developing the energy system. The conflict of commercial interests with the physical needs of the energy system causes the need to introduce the capacities market as a complementary segment to the electric energy commodity market. Ukraine has determined that the capacities market will function in the form of competitive procedures according to the targeted scope-oriented approach. Ukrainian capacities market has not yet been launched, but it is already possible to assume its potential ineffectiveness and inefficiency. Significant disadvantages of the electric energy cycle of Ukraine prove the insufficiency of a targeted approach to its organization. In addition, there are also pathological systemic problems with regard to the electrical energy industry of Ukraine (narrow diversification, inflexibility, heavy overtime load of power units, isolation and rapid development of renewable sources of electricity generation). The article proposes an alternative model of Ukrainian capacities market, which provides for: the organization of the balancing capacities market for the preliminary dispatching of both physical and commercial electric energy flows in the energy system; formation of the market of traditional capacities to ensure the adequacy of the development of the energy system; development of the market of alternative capacities for the integration of renewable electric energy generation, taking into account the requirements of flexibility of the energy system. The authors have identified significant advantages of this model compared to the proposed one, which will ensure operational security of electricity supplies and adequacy of the development of the energy system.

A Comprehensive Review of Power Flow Controllers in Interconnected Power System Networks

Energy security is one of the most crucial factor in the development of any nation. Interconnections among different power system networks are made to lower the overall price of power generation as well as enhance the reliability and the security of electric power supply. Different types of interconnection technologies are employed, such as AC interconnections, DC interconnections, synchronous interconnections, and asynchronous interconnections. It is necessary to control the power flow between the interconnected electric power networks. The power flow controllers are used to (i) enhance the operational flexibility and controllability of the electric power system networks, (ii) improve the system stability and (iii) accomplish better utilization of existing power transmission systems. These controllers can be built using power electronic devices, electromechanical devices or the hybrid of these devices. In this paper, control techniques for power system networks are discussed. It includes both centralized and decentralized control techniques for power system networks. This paper also presents a comprehensive review of HVDC interconnections, asynchronous AC interconnections, synchronous AC interconnections and different types of power flow controllers used in these interconnections. Moreover, some important and multivariable flexible AC transmission system (FACTS) devices such as UPFC and IPFC are also discussed with their merits and limitations. Finally, a new asynchronous AC link called flexible asynchronous AC link (FASAL) system is also described in detail. At last, a summary of the comparative analysis of power system link and power flow controllers is given based on recent publications. More than 400 research articles and papers on the topic of power transfer control are covered in this review and appended for a quick reference.

Comprehensive resilience assessment of electricity supply security for 140 countries

Abstract Indicator-based approaches are suitable to assess multi-dimensional problems. In order to compare a set of alternatives, one strategy is to normalize individual indicators to a common scale and aggregate them into a comprehensive score. This study proposes the Electricity Supply Resilience Index (ESRI), which is a measure of a nation’s electricity supply resilience. Starting from an initial set of individual indicators derived through a structured selection process, the ESRI is calculated for 140 countries worldwide. To account for robustness of the resulting resilience index, 38 combinations of eight normalization methods and six aggregation functions were considered. Results show a clear country ranking trend, with robust top- and low-performing countries across all combinations. However, the ranking disparity becomes large for average performing countries, especially if their indicators show high variability. Furthermore, the differences of the rankings are quantified through the Rank Difference Measure (RDM), which identifies the categorical scales and the minimum aggregator as the most different ones. Finally, the effects of different compensation levels of the aggregation functions are discussed. The findings of the present study aim to provide recommendations for policymakers on how composite indexes results depend on assumptions and chosen approaches.

Determining an accurate fault location in electrical energy distribution networks in the presence of DGs using transient analysis

Distributed generation resources are becoming more popular in electric energy distribution networks. As more Distributed generation are integrated into the grid, the system performance is challenged by issues such as manifold power injection to the network or nonlinear behavior when a fault occurs. To address this, fault location in electric energy distribution networks in the presence of distributed generation needs particular attention. This is important to reduce the loss of generated energy, reduce interruptions time, increase the reliability of the network and consequently improve the security of electricity supply. In this paper, a novel fault location method is presented applied to distributed networks with distributed generation. The proposed method is a hybrid two-step method which identifies accurate fault location using information stored in the network at pre- and post-fault time. The proposed method employs voltage and current information at the beginning of the feeder to estimate fault distance in the first step. The estimated distance will be associated with several similar sections considering the topology of the distributed networks. In the second step, the proposed method determines accurate fault location through transient analysis based on the frequency component. In this step, the exact fault location is identified. In order to investigate its performance, a standard IEEE-11 network is simulated in MATLAB. Furthermore, experiments are carried out in a network power simulator, showing good results.

REVIEW AND ANALYSIS OF ENERGY STORAGE SYSTEMS BY HYDRO-PUMPING TO SUPPORT A MIX OF ELECTRICITY GENERATION WITH A HIGH PERCENTAGE OF RENEWABLES

In some countries the planning of the electricity generation mix for the future includes a considerable increase in Renewable Energy (RE) to reduce the emissions caused by the use of fossil fuels. This trend can be reinforced if the installed power capacity of nuclear and coal plants is considerably decreased. On the other hand future electricity demand seems srt to increase due to population growth and greater domestic electrification, especially if transport electrification is tackled. The combination of these factors may result in an ever greater decline in Security of Supply (SoS), mainly due to the stochastic nature of electricity supply and demand behaviour. To achieve an acceptable level of SoS when introducing renewable energy into the grid it is necessary to increase storage capacity and tackle other measures such as demand management. Many energy storage technologies can be found, and Pumped Hydro Energy Storage (PHES) is recognised as the most mature, though other technologies such as batteries are also available. In this paper, we first review PHES and its abilty to support intermittent generation from energy plants, such as wind and solar, preventing energy losses and storing energy for use at times of high demand; second we analyse the performance of PHES in Spain over five years (2014-2018); our conclusion confirms that adequate SoS cannot be guaranteed with PHES management of the kind observed in the past. Keywords: security of electricity supply, adequacy of generation, pumped hydro storage facilities, uncertainty, Tobit model.

The Role of Domestic Integrated Battery Energy Storage Systems for Electricity Network Performance Enhancement

Low carbon technologies are necessary to address global warming issues through electricity decabonisation, but their large-scale integration challenges the stability and security of electricity supply. Energy storage can support this transition by bringing flexibility to the grid but since it represents high capital investments, the right choices must be made in terms of the technology and the location point in the network. Most of the potential for storage is achieved when connected further from the load, and Battery Energy Storage Systems (BESS) are a strong candidate for behind-the-meter integration. This work reviews and evaluates the state-of-the-art development of BESS, analysing the benefits and barriers to a wider range of applications in the domestic sector. Existing modelling tools that are key for a better assessment of the impacts of BESS to the grid are also reviewed. It is shown that the technology exists and has potential for including Electric Vehicle battery reuse, however it is still mostly applied to optimise domestic photovoltaic electricity utilisation. The barriers to a wider integration are financial, economic, technical, as well as market and regulation. Increased field trials and robust numerical modelling should be the next step to gain investment confidence and allow BESS to reach their potential.

Field validation of a standard Type 3 wind turbine model implemented in DIgSILENT-PowerFactory following IEC 61400-27-1 guidelines

Transient stability analyses are one of the key tools used to ensure grid stability and safeguard security of electricity supply, as well as to comply with different countries grid interconnection agreements. Transmission and distribution system operators require validated wind turbine models to perform these studies. This is becoming increasingly important in current power systems because wind energy penetration is constantly expanding, and its integration has a significant impact on power grid planning and operation. The definition of generic wind turbine models by international standard IEC 61400-27-1, first released in February 2015, aims to deal with this issue. Therefore, since the validation process of the most widely used model defined by this standard and one of the most technically advanced, the generic type 3 wind turbine, i.e., the doubly-fed induction generator, has only been conducted using non-specialised software tools in the field of electrical engineering, the present paper addresses the validation process of this WT when simulated in one of the leading electric power system analysis software tools: DIgSILENT-PowerFactory. The model is subjected to voltage dips of varying magnitude and duration, under both full and partial load conditions. The results are compared to field measurement data according to IEC 61400-27-1 guidelines, and validation errors are estimated.

Phasing-Out Coal in Germany – not only, but also a Legal Challenge

This article critically analyses recent developments in Australia's renewable energy law and policy. It identifies seven retrograde steps taken in energy and climate law in Australia in the last five years. Barriers to clean energy law - in the form of recurring narratives employed against the rise of renewable energy across Australia - are examined. Increased levels of renewable energy are portrayed by opponents as a threat to the security and reliability of electricity supply. Yet, the nation is currently experiencing a major renewable energy investment boom, supported by regional policy initiatives that are driving innovation, most recently in energy storage.

Influential factor analysis of China's unsustainable electric power system: A case study of Chengdu Electric Bureau

Electric security is closely related to all aspects of the national macro-economy, but when it comes into considering power policies, the subject of exploring the reasons for large area power outages is often considered as a “separate subject”. This paper proposes a novel evaluation method to analyze and determine the main factors that are commonly found within unsustainable electric power system. This method integrates the fuzzy clustering method, fault tree analysis and an analytic hierarchy process. First, it builds a classification for different factors based on Faulty Tree Analysis methods. Then, the logical relationships between each factors are prioritized and determined. Once the logical hierarchies are established, the Entropy-House of Quality for quantitative analysis is employed to support big blackout prevention and decision-making for various influential factors. Finally, Sichuan province are given to verify its effectiveness so that the policy-makers and security regulators in China can follow its recommendations to create a better electricity supply security management and a more sustainable energy reform in the future.

Evaluation of the subsurface compressed air energy storage (CAES) potential on Gotland, Sweden

Wind energy is an important field of development for the island of Gotland, Sweden, especially since the island has set targets to generate 100% of its energy from renewable sources by 2025. Due to the variability of wind conditions, energy storage will be an important technology to facilitate the continued development of wind energy on Gotland and ensure a stable and secure supply of electricity. In this study, the feasibility of utilizing the Middle Cambrian Faludden sandstone reservoir on Gotland for Compressed Air Energy Storage (CAES) is assessed. Firstly, a characterization of the sandstone beneath Gotland is presented, which includes detailed maps of reservoir thickness and top reservoir structure. Analysis of this information shows that the properties of the Faludden sandstone and associated cap rock appear favorable for the application of CAES. Seven structural closures are identified below the eastern and southern parts of Gotland, which could potentially be utilized for CAES. Scoping estimates of the energy storage capacity and flow rate for these closures within the Faludden sandstone show that industrial scale CAES could be possible on Gotland.

A survey on electricity market design: Insights from theory and real-world implementations of capacity remuneration mechanisms

In recent years, electricity markets have been characterized by a growing share of fluctuating renewable energies, which has increased concerns about the security of electricity supply. As a consequence, existing market designs are adapted, and new capacity remuneration mechanisms are introduced. However, these mechanisms entail new challenges, and it is disputed whether they are indeed needed. In this article, an overview of the current debate on the necessity of capacity remuneration mechanisms is provided. Furthermore, initial experiences of real-world implementations are discussed, and common findings in the literature, categorized by their economic implications, are derived. Finally, shortcomings in existing research and open questions that need to be addressed in future works are pointed out.

Development of electric power network infrastructure in aspect of electric energy supply security – case study Poland

In this paper, an analysis of issues related to development of national electric power network infrastructure in aspect of electric energy security is performed. Profile of network infrastructure in area of transmission and distribution is performed. Threats for electric energy supply security connected with transmission and distribution infrastructure are discussed. Both transmission and distribution electric power network are adapted for presently occurred typical conditions of electric energy demand and realization of internal tasks in normal conditions, but can create potential threat for electric energy supply security. In the context of forecasted increase of electric energy demand, inadequate power in National Electric Power System (NEPS) in domestic sources and available through intersystem connections, uneven location of sources and consumers at shortage of proper network transmission capacities, necessity of improvement of quality and electric energy supply reliability to final consumers and intensive development of renewable energy sources, present network infrastructure in area of transmission and distribution will be insufficient. Development of 400 and 220 kV transmission network, 110 kV distribution network especially in area of cities, MV distribution network especially in rural areas and realization of investments for improvement of export-import possibilities of NEPS will be necessary. Challenges for transmission and distribution system operators in area of network development are performed. They concern mainly investment sphere and area connected with preparation and construction of network investments.

Power quality enhancement in electricity grids with wind energy using multicell converters and energy storage

In recent years, the wind power industry is experiencing a rapid growth and more wind farms with larger size wind turbines are being connected to the power system. While this contributes to the overall security of electricity supply, large-scale deployment of wind energy into the grid also presents many technical challenges. Most of these challenges are one way or another, related to the variability and intermittent nature of wind and affect the power quality of the distribution grid. Power quality relates to factors that cause variations in the voltage level and frequency as well as distortion in the voltage and current waveforms due to wind variability which produces both harmonics and inter-harmonics. The main motivation behind work is to propose a new topology of the static AC/DC/AC multicell converter to improve the power quality in grid-connected wind energy conversion systems. Serial switching cells have the ability to achieve a high power with lower-size components and improve the voltage waveforms at the input and output of the converter by increasing the number of cells. Furthermore, a battery energy storage system is included and a power management strategy is designed to ensure the continuity of power supply and consequently the autonomy of the proposed system. The simulation results are presented for a 149.2 kW wind turbine induction generator system and the results obtained demonstrate the reduced harmonics, improved transient response, and reference tracking of the voltage output of the wind energy conversion system.

Survey based characterisation of energy services for improved design and operation of standalone microgrids

Microgrids for rural electrification are expected to play a key role in achieving global energy access goals. However, the high cost of stand-alone microgrids intended to serve generally poor communities remains a key barrier to their deployment, while design and operation is challenging, given generally low diversity of loads and generators, and often high penetrations of variable renewable generation.Current practices for providing electricity access still often focus on the supply side with an emphasis on ensuring the reliability, affordability and security of electricity supply to meet user demand. This supply focus misses some key opportunities on the demand-side for providing low cost and reliable energy service delivery. In particular, rural communities may place very different relative values on various energy services, while there may be considerable flexibility in terms of when some of these energy services are delivered; due to inherent energy storage in the end-use equipment, or user willingness to shift the energy service itself.This paper presents a novel characterisation framework for energy services based on their relative flexibility and consumer prioritisation. Detailed survey data from 154 households across five microgrid sites in Nepal is used to test this framework, and assess the potential insights that it can provide for microgrid designers and operators seeking to reduce costs and improve reliability when serving poor rural communities. The five microgrids represent very different energy services and microgrid technology contexts, yet all would appear to have demand-side management opportunities that can trade-off cost and reliability and prioritise loads according to user preferences.

Australian Renewable Energy Law: Carbon Lock-in or Clean Energy Transition?

This article critically analyses recent developments in Australia's renewable energy law and policy. It identifies seven retrograde steps taken in energy and climate law in Australia in the last five years. Barriers to clean energy law - in the form of recurring narratives employed against the rise of renewable energy across Australia - are examined. Increased levels of renewable energy are portrayed by opponents as a threat to the security and reliability of electricity supply. Yet, the nation is currently experiencing a major renewable energy investment boom, supported by regional policy initiatives that are driving innovation, most recently in energy storage.

Australian Renewable Energy Law: Carbon Lock-In or Clean Energy Transition? The Pursuit of Policy Stability and Energy Security at Higher Levels of Renewable Generation

This article critically analyses recent developments in Australia’s renewable energy law and policy. It identifies seven retrograde steps taken in energy and climate law in Australia in the last five years. Barriers to clean energy law - in the form of recurring narratives employed against the rise of renewable energy across Australia - are examined. Increased levels of renewable energy are portrayed by opponents as a threat to the security and reliability of electricity supply. Yet, the nation is currently experiencing a major renewable energy investment boom, supported by regional policy initiatives that are driving innovation, most recently in energy storage.

Small-scale 5.1 kW wind turbine on-grid connected for outdoor illumination of a small residential district

In this paper a power supply system based on 5.1 kW wind turbine on-grid connected used for outdoor illumination of a small residential district is analysed. The wind resource for the proposed site is obtained mainly from NASA Surface meteorology and Solar Energy database. The load demand curve is obtained analysing the cadastral map of the residential district, the illumination requirements for road lighting, the road luminaire arrangement, the technical specification of the luminaire and the number of operating hours per year. The illumination system design is performed using DIALux software. The on-grid power supply system is analysed using HOMER software. Three sensitive parameters are considered: the annual average wind velocity, the hub height, and the carbon dioxide penalties, for which 150 different power supply systems are computed and analysed with the HOMER software. Considering the net present cost as the objective function, an optimal curve is obtained which allows to decide which power supply systems are prohibitive and which are feasible. The security of electric power supply of the system analysed in this paper is provided by the grid itself, the renewable power source being responsible for decreasing the CO2 emissions produced by the combustion of fossil fuels.

Physical adequacy of a power generation system: The case of Spain in the long term

Generation adequacy is a key ingredient to security of electricity supply. We develop a stochastic model of demand and supply (from different technologies) for measuring it from a physical or technical point of view. We adopt several metrics of supply shortfalls. Next we demonstrate the model by example. Because of limited interconnections with neighboring countries, Spain can be considered an electric island. We get numerical estimates of the parameters underlying the model. We then resort to Monte Carlo simulation to derive the risk profile of the adequacy metrics in the coming decades. We consider up to ten scenarios, with different demand paths and generation parks. The proposed deployment of renewable technologies and the envisaged closure of coal-fired and nuclear stations result in greater risk of shortages. For one, assuming that demand grows at 1.36% per year, from 2020 to 2030 the expected energy not served increases more than 400-fold as coal and nuclear capacities are reduced; the factor runs into the tens of thousands by 2040 and 2050 when those technologies cease to operate. These results are potentially important for policy makers, system operators, and power companies involved in the construction of the European internal electricity market.

India's sustainable development goals – Glide path for India's power sector

India has adopted the 2030 Agenda during the United Nations Summit held in September 2015. Energy is intimately connected with 74% of the 169 targets related to the 17 Sustainable Development Goals (SDGs) to be achieved by 2030. Subsequently, India has also submitted its Nationally Determined Contributions (NDCs) for the period 2021–2030 to the United Nations Framework Convention on Climate Change (UNFCCC). While the Government of India (GOI) has ambitious plans for enhancing the installed capacity of RE sources, 75% of its electricity is currently generated by coal-fired power plants. As India's electricity requirements grow to meet the aspirations of 1.3 Bi people, it needs a policy framework that integrates all low-carbon energy technologies with coal in such a manner that the reliability, security, and affordability of electric supply are balanced with sustainable development. India also needs to develop innovative strategies to clean up the country's coal sector while enhancing the integration of renewable energy into the National Power Grid. In this context, certain recommendations are proposed in this article for timely implementation by GOI to facilitate the achievement of India's targets with respect to SDG 7 and the NDCs in an efficient and effective manner.