Efficiency Of Power Grid Research Articles

Development of a device for control of electric energy parameters in the distribution network

Background: As of today, the actual problem in the power sector is to create a device for the collection and transmission of information in networks of different voltage levels.
 Aim: The research presented in the framework of this article is aimed at creating a universal device intended for use in electrical networks of low and medium voltage in order to collect and transmit information about the parameters of electrical energy at the place of installation of the device.
 Methods: The study was performed with the use of computer modeling techniques developed electronic devices.
 Results: A functional diagram of the developed device is given, options for its connection to the network for various conditions and requirements are indicated, and recommendations for use are given.
 Conclusion: The obtained results can be used by power grid companies and industrial enterprises to analyze the condition and efficiency of power grids.

A deep learning‐based classification scheme for cyber‐attack detection in power system

A smart grid improves power grid efficiency by using modern information and communication technologies. However, at the same time, the system might become increasingly vulnerable to cyberattacks. Among various emerging security problems, a false data injection attack (FDIA) is a new type of attack against the state estimation. In this article, a deep learning-based identification scheme is developed to detect and mitigate information corruption. The scheme implements a Conditional Deep Belief Network to analyse time-series input data and leverages captured features to detect the FDIA. The performance of the detection mechanism is validated by using the IEEE standard test system for simulation. Different attack scenarios and parameters are set to demonstrate the feasibility and effectiveness of the developed scheme. Compared with the support vector machine and the multilayer perceptrons, the experimental analyses indicate that the results of the proposed detection mechanism are better than those of the other two in terms of FDIA detection accuracy and robustness.

Development of a system for control of electric energy parameters in the distribution network

Background: The creation and distribution of technical means and complexes aimed at building effective control systems for electrical networks using information that can be collected by modern metering devices, as well as organizing work in an automated mode, is an urgent task at the present stage of development of the electric power industry in Russia and in the world.
 Aim: The research presented in this article is aimed at creating an effective system for monitoring the parameters of electrical energy in distribution networks of low and medium voltage levels.
 Methods: The study was carried out using the theoretical foundations and basic laws of electrical engineering, as well as methods of computer modeling and CAD.
 Results: A description of the developed system is given, the applicability of its use is graphically shown and substantiated in writing, the possibilities and prospects of application are indicated, and recommendations for practical application are given.
 Conclusion: The results obtained can be used by power grid companies to analyze the state and efficiency of power grids, and may also be of interest to researchers working on the creation of digital twins of power grids.

A Deep Learning-Based Classification Scheme for False Data Injection Attack Detection in Power System

A smart grid improves power grid efficiency by using modern information and communication technologies. However, at the same time, due to the dependence on information technology and the deep integration of electrical components and computing information in cyber space, the system might become increasingly vulnerable to cyber-attacks. Among various emerging security problems, a false data injection attack (FDIA) is a new type of attack against the state estimation. In this article, a deep learning-based identification scheme is developed to detect and mitigate information corruption. The scheme implements a conditional deep belief network (CDBN) to analyze time-series input data and leverages captured features to detect the FDIA. The performance of our detection mechanism is validated by using the IEEE 14-bus test system for simulation. Different attack scenarios and parameters are set to demonstrate the feasibility and effectiveness of the developed scheme. Compared with the artificial neural network (ANN) and the support vector machine (SVM), the experimental analyses indicate that the results of our detection mechanism are better than those of the other two in terms of FDIA detection accuracy and robustness.

Testbed implementation of reinforcement learning-based demand response energy management system

Demand response (DR) has been acknowledged as an effective method to improve the stability, and financial efficiency of power grids. During operation of a DR program, there are usually multiple interactions among different grid entities, which complicates decision-making processes with respect to grid operations. Recently, reinforcement learning (RL) has attracted increasing attention for managing complex decision-making problems, owing to its self-learning capacity. Several theoretical RL-based approaches have been proposed for addressing various DR issues, but the practical feasibility of these theoretical approaches remains to be proven. In this paper, a conceptual architecture is firstly proposed to support DR management of a diversified facility in the context of a price-based DR environment. Secondly, exhaustive guidelines are provided to illustrate how to implement a multi-agent RL-based algorithm in the constructed DR management system. Afterwards, a laboratory-level testbed was set up to evaluate the effectiveness of the deployed DR algorithm. The experimental evaluation results show that the RL-based DR algorithm takes about 20s and 50 episodes to achieve optimal load control policy. By executing the optimal operation policy, the overall energy consumption during the highest price period (i.e., 15:00–18:00) is significantly reduced by 133.6% compared with the lowest price period (i.e., 02:00–05:00).

Research on Comprehensive Evaluation Method of Power Grid Efficiency

Power Grid Efficiency directly affects the development level of the company and is an important embodiment of the company’s comprehensive strength and market competitiveness. Different from the previous single cause analysis, this paper uses the earned value method to evaluate the project progress objectively and systematically, and establishes the relevant evaluation index system, so as to have certain reference value for the company’s decision-making adjustment.

Research on Load Balancing Dispatching Method of Power Network Based on Cloud Computing

With the continuous development of big data era and cloud computing(CC) technology, there are still a series of problems in the planning performance and related algorithms of CC grid, such as unbalanced grid load and uneven grid spatial distribution. However, with the continuous development of social economy and the continuous improvement of people’s living standards and quality, the scale of power grid construction is also expanding, the load distribution of power grid is unbalanced, and the power distribution capacity is insufficient. In order to effectively analyze the load balance and scheduling of power grid, CC technology can accurately improve the accuracy of data analysis and processing. In the process of network load balancing and distribution, the use of CC can not only improve the scheduling efficiency, but also improve the quality and speed of work. Aiming at the problem of poor scheduling performance, this paper proposes a fuzzy iterative algorithm and applies it to CC environment. Plan load balancing for the current network. The experimental process of the algorithm is introduced in detail, the balanced distribution parameters of the load data are extracted, and the load model is established. Realize and improve the network load balance distribution. Experimental results show that the proposed method can improve the load balancing configuration of power grid, improve the management efficiency of power grid, and has good experimental performance.

Thermal analysis of 22.9-kV crosslinked polyethylene cable joint based on partial discharge using fiber Bragg grating sensors

Thermal effects of power cables are critical factors for determining the remaining lifetime and efficiency of power grids. Herein, we propose a fiber Bragg grating (FBG) sensor package with high-temperature sensitivity. Using polyacetal, which has a higher coefficient of thermal expansion than typical optical fibers, we constructed the proposed sensor structure. The developed sensor exhibited about 14.1 times higher temperature sensitivity than a typical bare FBG sensor. To measure the temperature variation of power cable joints caused by partial discharge, we constructed a mock system similar to a manhole, and we installed the developed sensor at a 22.9-kV crosslinked polyethylene cable joint. The experimental result reveals that even a slight temperature difference of 0.2°C can be measured using PD (300 pC at 20 kV).

Using Improved MPPT Charge Controller Improvement Functioning Efficiency of Power Grid Connected Solar Photovoltaic System

In recent decades, the world’s energy demand is closely linked to the rise of manufacturing, transport and the media. Today, large amount of the power is provided by non-renewable energy including coal, natural gas, oil and uranium. Pace of regeneration of energy is very sluggish, which adds to the possibility of short-term depletion. This paper focuses on power grid-connected photovoltaic systems. The primary objective is to regulating power pumped into the grid from solar panels and improving the configuration and regulation of inverters as used to supply electricity to the grid with optimum efficiency and according to networking requests as an interface between the grid and photovoltaic systems. The infused power management not only contains the aggressive force control but also the reactive power control. An algorithm is proposed for the design of a simple and robust grid-connected inverter power. It is based on the strategy for digital power. The proposed work analyses and improves the constraints of the VSCs’ Voltage Source Converters as converters for supplying active and reactive power into the grid, ensuring the best possible connection from the solar panels, ensuring effective operation of the inverter, increasing the current injection into the grid power and harmonic levels.

Small Renewable Energy Community: The Role of Energy and Environmental Indicators for Power Grid

The Clean Energy for all Europeans Package pushes for the diffusion of renewable energy communities, introducing their definition in the European legislative framework. Following this interest, this paper analyses the energy and environmental performance of a renewable energy community composed of two office buildings located in Naples (Italy). Each building has a rooftop photovoltaic plant and one office presents an electric vehicle. The heating and cooling demands of both offices are satisfied by two reversible air to water heat pumps. The offices are connected through an electric microgrid and they are in parallel with a power grid. Buildings and plants are modelled and simulated by means of TRNSYS 17 simulation software. The first analysis has concerned the comparison of the results achieved in renewable energy community configuration and from individual buildings in terms of quantity of electricity imported, exported from/to power grid and consumed on-site. The share of self-consumed photovoltaic electricity rises up to 79% when energy sharing is allowed. The second analysis has been carried out to evaluate the energy and environmental performance of a renewable energy community by means of fixed and hourly varying values for power grid efficiency and emission factors for electricity. The use of time-dependent indicators has led to a lower community primary energy demand and carbon dioxide emissions of 18% and 12%, respectively, in comparison with the scenario in which the fixed parameters have been adopted.

Research on new transmission network planning considering adjustable comprehensive resources

With the large-scale renewable energy grid integration, the problems of traditional transmission network planning methods, such as high investment, low utilization rate and difficulty in implementation, have gradually emerged. Therefore, in order to improve the level of new energy consumption, effectively improve the operation efficiency of power grid and optimize the investment benefit, this paper proposes a new mode of power grid planning based on adjustable integrated resources. This paper focuses on two key planning methods: new energy confidence capacity assessment methods and load forecasting methods considering demand side resources.Then the paper takes a city-level 220 KV power grid as an example, applies a new power grid planning method to carry out planning, and verifies the effectiveness of the proposed planning model and method.

Application of Matter Element Analysis in Power Grid Development Diagnosis

The structure and form of modern power grids are becoming more and more complex, and there are many indicators and factors that need to be considered to evaluate the development status of the power grid. In order to diagnose the development level of power grid, the index system is reconstructed, which includes seven dimensions: the coordination of power grid development speed, the coordination of power grid development scale, the coordination of power grid structure, the security and reliability of power grid, the level of equipment, the utilization efficiency of power grid and the development benefit of power grid, the construction principle and index selection basis are given. When dealing with contradictory problems in reality, methods combining quantitative and qualitative can be applied to study. The matter element analysis method is applied to power grid development diagnosis, and a model of power grid development diagnosis based on matter element analysis is established, the model can not only diagnose the development level of power grid, but also determine the key factors that affect the diagnosis results, and give suggestions for improvement. The practical example verifies the feasibility and rationality of the method, which has good evaluation accuracy and prediction effect.

Study on Operation Parameter Characteristics of Induction Filter Distribution Transformer in Low-Voltage Distribution Network

There is a need for induction filter technology in the field of low-voltage distribution networks. This paper proposes an induction filter distribution transformer with a unique Dd0yn11 three-winding configuration. This approach allows for the control of load side harmonics in low-voltage distribution networks. At present, the induction filter technology proposed in the known literature is mostly used in the high-voltage power system, but there is still no research on the application of induction filter technology to the distribution transformer with Dyn11 under the low-voltage distribution network. In this paper, the wiring scheme of inductive filter distribution transformer and filter system in low-voltage distribution network is established firstly, then the mathematical relationship between the harmonic current generated by the load side and the current on the grid side is derived according to the winding model, and it can be deduced that the induction filter distribution transformer with its filtering system has good filtering performance and reactive power compensation characteristics. Finally, the experiment simulates the three-phase harmonic load, detects the current waveform and other parameters of the actual grid side of the new transformer, verifies the correctness of the theoretical analysis. The induction filter distribution transformer proposed in this paper provides a new solution for harmonic suppression and reactive power compensation in low-voltage distribution network, which fills the vacancy of the application of induction filter technology in low-voltage distribution network, This paper reveals that the inductive filter technique has a good filtering performance when applied to low-voltage distribution network. And it provides a reference for further research on improving power grid efficiency, saving energy cost and improving transformer electromagnetic environment under low-voltage distribution network.

Online Evaluation System of Power Grid Efficiency

Transmission network is an important part of power system. The operation efficiency of transmission network is one of the important indexes of power system. At present, there is still much room to improve the efficiency of China's transmission network. There is a lack of a suitable system to evaluate the operation efficiency of transmission network. In order to effectively evaluate the efficiency of transmission network, this paper establishes the evaluation index system of transmission network operation efficiency and applies it to the actual power system. The test results verify the feasibility of the proposed index system.

Construction And Application of Investment Execution Analysis Index System for Distribution Network Infrastructure Projects

With the slowdown of external economic growth, more stringent review of investment execution, and in-depth promotion and implementation of transmission and distribution price reform, the implementation of lean management of state grid investment has been accelerated. The improvement of lean management level of 10kV projects, which account for more than half of the investment in power grid infrastructure, plays a greater role in promoting the overall investment efficiency of power grid. The lean management of power grid investment emphasizes “scientific decision making before investment - precise implementation in the event - scientific evaluation after the event”. From the perspective of investment lean management - strengthening the precise implementation in the matter, this paper takes the power grid infrastructure projects of 10kV and below as the research object, through combing the management key points and relevant management requirements of key nodes in the whole process, from the aspects of compliance, rationality and effectiveness of investment execution, this paper sorts out and determines the investment execution analysis indicators and evaluation rules, which provides the basis for the next step of investment execution index scenario application, and also provides support for comprehensively improving the lean management level of investment in 10kV and below power grid infrastructure projects.

Energy and environmental performance of a heat pump in different power grid scenarios

Electric-driven heat pumps are one of the most encouraging systems that could support the raising of renewables contribution in civil sector energy consumption, especially with reference to the Countries with a high contribution of renewable energy sources in electricity generation mix. However, the evaluation of the effective energy and environmental performance of an electric heat pump meeting the space heating and cooling requests of a building has to consider several factors that affect the results. Among them great attention should be given to the variability of weather conditions in which the system operates, the changeability of the efficiency and environmental indicators of power grid. The analysis becomes more complex if the variation of these parameters is considered in terms of time and geographic location but it leads to the actual evaluation of the energy conversion system performance that is neglected by European Regulations. This paper presents an energy and environmental analysis of an electric-driven air-source heat pump providing the space heating and cooling needs of the same building located in two different geographical locations by means of a dynamic simulation performed in TRNSYS 17. The analysis is carried out considering the average and time-dependent values of the carbon dioxide emission factors for electricity and the power grid efficiency indicators evaluated by means of the real electricity generation data. In addition, the paper proposes the evaluation of the average and hourly energy and environmental parameters referred only to the electricity market zones in which the buildings are located. These indices are considered in the analysis too. The results have highlighted that the assessment based on average and high-resolution parameters, as well the evaluation based on indicators referred to electricity market zones only, could return very different outcomes leading to a significant overestimation or underestimation of the energy and environmental performance of the system based on the electric-driven heat pump. Finally, a further analysis has been carried out to determine how the results can vary considering the average value of the electric efficiency indicator suggested by Italian Regulations and that of other European Countries.

Comparison of Two Solar PV-Driven Air Conditioning Systems with Different Tracking Modes

In this paper two solar electric-driven air conditioning systems are compared and analyzed from an energy and environmental point of view. Both systems satisfy the electricity, space heating and cooling needs of an existing multi-purpose, multi-story building that is simulated with TRNSYS 17. The first one, considered as reference system, is based on a centralized electric heat pump coupled with a conventional photovoltaic plant installed 10 years ago. The second one, hereinafter proposed system, has a hybrid configuration, consisting of a ground-source heat pump, a low temperature thermal network and a series of electric heat pumps, one per apartment. In addition, the plant is connected to a high-performance commercial photovoltaic system equipped with a solar tracking system to the panels. Five different solutions realized with vertical, two horizontal orientations, polar and two-axis trackers are taken into account and compared with the standard fixed configuration. The last hybrid configuration can be seen as an upgrade of an existing decentralized air conditioning system in which the local electric heat pumps are converted in water-to-water devices that interact with the thermal grid representing the heat source/sink for them. In both solar electric heating and cooling plants the photovoltaic system is installed on the building roof and it produces electricity to feed the heat pumps and end-users. The electricity surplus or the load not covered by solar field is fed to/taken from power grid. The energy and environmental analyses have been performed by considering both average annual and monthly values of power grid efficiency and CO2 emission factor for electricity. By comparing reference system and proposed one equipped with a two-axis tracker system a primary fossil energy saving of 101.67% is achieved in summer period and 28.10% in winter period. These percentages are the highest values recorded, even if, for all configurations the energy analysis rewards the proposed system. The results of environmental analysis demonstrate that the reference system has the worst performances compared to proposed system with all solar tracker systems selected guarantying positive values for avoided carbon dioxide index up to 45.86%.

Distributed control of electric vehicle fleets considering grid congestion and battery degradation

Nowadays, developing coordinated optimal charging strategies for large‐scale electric vehicle (EV) fleets is crucial to ensure the reliability and efficiency of power grids. This paper presents a novel fully distributed control strategy for the optimal charging of large‐scale EV fleets aiming at the minimization of the aggregated charging cost and battery degradation, while satisfying the EVs' individual load requirements and the overall grid congestion limits. We formulate the optimization problem as a convex quadratic programming problem where all the EVs' decisions are coupled both via the objective function and some grid resource sharing constraints. Based on the distributed waterfilling approach, the proposed resolution algorithm requires a minimal shared information between EVs that communicate only with their neighbors without relying on a central aggregator, thus guaranteeing the EV users' privacy. The performance of the proposed approach is evaluated through numerical experiments to validate its effectiveness in achieving a global optimum while respecting the grid constraints with a favorable computational efficiency.

How different power grid efficiency scenarios affect the energy and environmental feasibility of a polygeneration system

Combined heat and power generation traditionally allows for higher energy performance than separate production of heat and electricity. However, the significant increase of the renewable energy sources contribution in electricity production has spatially and temporally modified the context in which polygeneration systems operate and the energy and environmental profitability of these technologies could be undetermined.In such a situation it seems interesting to investigate the influence of the power grid efficiency variation on the polygeneration systems performance. For this purpose energy and environmental performance of a proposed system based on combined production are compared to those achieved by a conventional system based on separate production. The primary energy demand of conventional and proposed systems due to electricity depends on the efficiency of the national electric energy system features. In this paper, this efficiency is considered to be time-varying (hour-by-hour) and it is further taken into account that the electric system efficiency changes in different regions of the same Country. According to Italian day ahead market of electricity the national territory is divided in 6 zones; two of them (Centre-North zone and Centre-South zone) will be specifically considered and compared hereinafter. The differences that arise in results are also assessed with respect to the case in which national and local average efficiency is taken into account. The environmental analysis is performed considering the average and the time-varying Italian and local electricity emission factors. The results have highlighted that the cogeneration system feasibility depends upon the variability of these factors. Indeed, referring to thermoelectric-based power grid efficiency, only in Centre-North zone is more energetically convenient to produce heat and power by separate production systems. The environmental analysis outcomes have showed the same trend of energy analysis results in all the considered zones underlining that the evolution towards sustainability in Smart Grids requires an integrated approach.

Review and Prospects for Evaluating Power Grid Dispatching Service Quality

To reasonably evaluate the dispatching service quality of a power grid and comprehensively reflect the diversified demand satisfaction extent of the relevant stakeholders in the power system, it is imperative to construct an evaluation index system for power grid dispatching service quality, which should thoroughly consider the demand satisfaction of generation-side stakeholders, grid-side stakeholders, and load-side stakeholders. In this paper, the research status of the source-grid-load stakeholders' satisfaction indexes is overviewed from the perspective of their dispatching demand. The dispatching demand satisfaction indexes of the source-grid-load stakeholders and major evaluation methods in the literature are also summarized. According to current research progress, proposals for improving the rationality and efficiency of power grid dispatching service quality evaluation are also described. Finally, by combining the development demands of power grid dispatching service quality, we outline future research directions that involve dispatching demand satisfaction indexes evaluation for source-grid-load stakeholders in the power system.