Microgrid Construction Research Articles

Low-carbon economic dispatch strategy for microgrids considering stepwise carbon trading and generalized energy storage

Integrating carbon trading mechanisms with generalized energy storage (GES) fully embodies the principles of green and coordinated development, serving as a crucial means to achieve low-carbon construction of microgrids. This research presents a strategy for optimizing energy allocation within microgrids to minimize carbon emissions and enhance microgrid systems' economic-environmental benefits. The strategy takes into account the use of tiered carbon trading and GES. Based on a typical microgrid system architecture, an economic dispatch model for microgrids is developed, which integrates renewable energy sources such as wind and solar storage, gas turbines, energy storage systems, and flexible resources on the demand side. The model aims to minimize carbon emissions while optimizing the allocation of resources. Subsequently, the model facilitates microgrid carbon emission control by considering the transferable, convertible, and reducible properties of GES. Furthermore, implementing a tiered carbon trading mechanism decreases carbon emissions. Finally, using a real microgrid example from a specific region in China, the results indicate that the proposed method significantly enhances the system's low-carbon level. Notably, compared to scenarios that do not consider GES, the proposed method substantially reduces total costs by 6.62% and decreases carbon emissions by 22.2%. The findings indicate that the suggested dispatch model can substantially decrease carbon emissions while simultaneously improving the economic efficiency of the microgrid system.

A frequency cooperative control strategy for multimicrogrids with EVs based on improved evolutionary-deep reinforcement learning

The construction of microgrid has fully promoted the large-scale access of distributed power and the rapid development of electric vehicles (EVs). And microgrid system faces operational issues such as strong random disturbances from distributed power sources and loads, as well as unexpected events during operation. These issues can lead to unstable microgrid frequency, excessive discharge of EVs, and increased control costs. To solve the issues, a frequency cooperative control strategy for multimicrogrids with EVs based on improved evolutionary-deep reinforcement learning (EDRL) is proposed in this paper. First, consider the effect of the vehicle-to-grid (V2G) process on the minimum time required to fully charge an EV, and the impact of the output distribution of micro turbines (MTs) on the regulation cost, and based on the coupling relationship between generator terminal voltage regulation and system frequency control, a multimicrogrid comprehensive control model is constructed. Second, in order to deal with engineering tasks with deceptive rewards and sparse rewards such as integrated frequency control, evolutionary algorithms and deep reinforcement learning algorithms are combined to effectively assist the training process to jump out of local optimal solutions and approach optimal control strategies. Meanwhile, the algorithm is improved based on the novelty search and intelligent partition strategy, so that the strategy has better convergence characteristics and can reduce the cost of information transmission and computational complexity under the premise of ensuring the control effect. Furthermore, the state space, action space and reward function of the controller are defined. Finally, the simulation results show that the proposed controller has the ability of coordinated control, can effectively reduce the adjustment cost of MT unit and the unnecessary discharging of EVs while ensuring the frequency regulation requirements of each submicrogrid, which is far superior to PID control, fuzzy control, and traditional deep reinforcement learning control.

Highway Microgrid Project Evaluation under Energy Transportation Integration

The construction of highway microgrids is evolving into a new highway energy system that integrates “Source-Network-Load-Storage”. This paper provides a comprehensive evaluation of expressway microgrids from the perspective of transportation and energy integration. An index model is set up that considers the economy, technology, and environment. The grey evaluation method, on the strength of analytic hierarchy process–entropy weight method, shows that the integrated microgrid of “source-network-load-storage” promotes energy sustainability, supply reliability, and sustainable environmental development. When compared to different evaluation methods for microgrid planning schemes, our method yields the highest score of 0.9127, indicating superior results. This approach is suitable for the multicomponent evaluation system of expressway microgrids and allows for scientifically evaluating microgrid planning schemes.

Integrating Demand Response with Unit Commitment in Insular Microgrid considering Forecasting Errors and Battery Storage

In this paper, DR programs are integrated with the unit commitment economic dispatch model for a single day to lower total operating costs for an insular microgrid. The proposed model takes into account the forecasting errors associated with wind, solar, and load demands. A new combined DR program is presented to enhance microgrid operation and financial effectiveness, benefiting microgrid consumers. The price elasticity and consumer profit are the foundation for DR modeling. The optimization problem is developed as mixed‐integer nonlinear programming (MINLP) and solved using GAMS software. For the case study, an insular microgrid consisting of two microturbines, a wind turbine, solar photovoltaic, and battery storage is considered. Optimization is carried out under both with and without the DR program. The outcomes show that by implementing TOU and DLC DR programs, the operating cost is reduced by 13.55% and 9.68%, respectively. While consumers experience a financial loss in TOU‐DR, they earn profit in DLC‐DR. Therefore, a combination of the two, i.e., TOU + DLC DR, is proposed, reducing operating costs by 10.73% while increasing profit for users. The suggested approach benefits the microgrid operator as well as its users, encouraging the construction and operation of insular microgrids in rural or isolated areas.

Smart microgrid construction in abandoned mines based on gravity energy storage

The share of new energy in China's energy consumption structure is expanding, posing serious challenges to the national grid's stability and reliability.As a result, it is critical to construct large-scale reliable energy storage infrastructure and smart microgrids. Based on the spatial resource endowment of abandoned mines' upper and lower wells and the principle characteristics of the gravity energy storage system, an intelligent microgrid system model for abandoned mines based on gravity energy storage is proposed, and the system's feasibility and key influencing factors are discussed and analyzed from the standpoint of economic benefits. The gravity energy storage system principle, system structure, subsurface powerhouse, underground storage, and transit system are all examined and analyzed.The viability of establishing intelligent microgrid systems in abandoned mines is proved using the resource conditions, technical conditions, economic advantages, and social benefits of Panyidong Mine in Huainan Coal Mine.The findings indicate that the project concept has good economic and social benefits as well as practical viability.Next, from the perspectives of technology, policy, and the ecological environment, several recommendations for the development of a smart microgrid system based on gravity energy storage power station are made. This study presents a novel concept for the advancement of energy storage technology and the reuse of abandoned mine resources, which is critical to the long-term development of abandoned mine resources and the advancement of energy storage technology.

Optimization of Expressway Microgrid Construction Mode and Capacity Configuration Considering Carbon Trading

An expressway microgrid can make full use of renewable resources near the road area and enable joint carbon reduction in both transportation and energy sectors. It is important to research the optimal construction mode and capacity configuration method of expressway microgrid considering the carbon trading and carbon offset mechanism. This paper establishes a design model for an expressway microgrid considering the operating features of each component in the microgrid under two patterns of grid-connected/islanded and two types of AC/DC. The goal of the proposed model is to minimize the annualized comprehensive cost, which includes the annualized investment cost, operational cost, and carbon trading cost. The model designates the optimal construction mode of an expressway microgrid, i.e., grid-connected or islanded, AC or DC. As a mixed integer nonlinear programming (MINLP) problem, the proposed model can be solved in a commercial solver conveniently, such as GUROBI and CPLEX. The validity and practicality of the proposed model have been demonstrated through case studies in several different application scenarios, which also demonstrate the necessity of considering carbon trading mechanisms in the design model.

Optimized Non-Integer Load Frequency Control Scheme for Interconnected Microgrids in Remote Areas with High Renewable Energy and Electric Vehicle Penetrations

Renewable energy systems (RESs) have introduced themselves as vital solutions for energy supply in remote regions, wherein main utility supply systems are not available. The construction of microgrid (MG) systems is useful candidate for proper control and management with hybrid RESs. However, RESs-based MGs face reduced power system inertia due to the dependency of RESs on power electronic converter systems. Accordingly, preserving nominal operating frequency and reduced deviations in tie-line power are crucial elements for proper operation of interconnected MGs in remote areas. To overcome this problem, load frequency control (LFC) systems have proven featured solutions. Therefore, this paper proposes a new non-integer LFC method based on the fractional order (FO) control theory for LFC in interconnected MGs in remote areas. The proposed control is based on the three degree of freedom (3DoF) cascaded 1+proportional-integral-derivative-accelerated (PIDA) controller with FOPI controller, namely 3DoF 1+PIDA/FOPI LFC scheme. The proposed 3DoF 1+PIDA/FOPItakes the advantages of the accelerated term of PIDA control to improve power system transients, regarding maximum overshoot/undershoot and settling times. Additionally, it employs outer loop to reduce errors and faster inner loop to mitigate disturbances effects. The contribution of plug-in controlled electric vehicles (EVs) are considered to enhance the frequency regulation functions. An optimized design of the proposed 3DoF 1+PIDA/FOPI LFC scheme is proposed using the newly developed hybrid equilibrium optimizer (EO)-slime mould optimization (SMA) algorithm (namely EOSMA optimizer). The EOSMA combines the features of the EO and SMA powerful optimization algorithms. A two interconnected MGs in remote areas with RESs and EVs inclusions with high penetration levels is selected to verify the proposed 3DoF 1+PIDA/FOPI LFC scheme and the EOSMA optimizer. The results show high ability of the proposed controller and design scheme to minimize MGs’ frequency and tie-line power fluctuations and to preserve frequency stability and security.

Optimal scheduling strategy of the hydrogen-electric coupled system considering source-load uncertainty

Hybrid energy storage systems are increasingly envisaged to be used in the construction of microgrids to alleviate the intermittency of renewable energy output and achieve large-scale penetration into the power grid. The hydrogen-electric coupled system (HECS) combines long-term hydrogen storage with short-term battery storage and realizes the conversion of multiple energy flows through power to gas and gas to power. However, the optimal scheduling of such a hybrid energy storage system is more complex than a single one. Faced with this issue, this paper proposed a HECS scheduling method based on the storage degradation cost to solve the power distribution problem. Furthermore, to reduce the impact of source-load uncertainty, the improved k-medoids method is used to extract representatively typical and extreme scenarios from the annual data to evaluate the economy and reliability of the system operation. According to the simulation result, we can conclude that the proposed method achieves cost-optimal scheduling by maximizing hydrogen production in the on-grid mode and reducing the battery cycle cost in the off-grid mode. Compared with the state machine control strategy, the proposed method has lowered the operation cost in all simulation scenarios and shows its effectiveness. Finally, the results show that the operation cost can be reduced by applying a demand response program, especially in the off-grid mode.

Research on the construction of new energy microgrids for wind power generation based on green and low carbon

At present, the supply mode of fossil fuel as energy in China has caused more and more damage to the environment. In order to meet the demand for sustainable development, research on the construction of new energy microgrids for wind power generation based on green and low-carbon is proposed. Firstly, the equivalent model of the wind power generation system is established, and then the wind power generation new energy microgrid with a wind turbine as the core is built based on the specific value calculated by the model. Finally, the conventional new energy microgrid construction scheme is selected as the comparative object, and the comparative experiment is carried out to prove the practicability of the method. The comparative experimental results show that the microgrid constructed by the proposed green and low-carbon wind power generation new energy microgrid construction method is superior to the traditional construction scheme in operating power, can meet the green and low-carbon energy development needs, and can provide a reference value for similar research schemes.

New Reliability Indices for Microgrids and Provisional Microgrids in Smart Distribution Systems

The construction of provisional microgrids paired with microgrids was recently introduced taking into consideration, the less critical zones of the distribution system. Similar to the microgrids, the provisional microgrids have distributed generators and a master controller. But these provisional microgrids cannot switch to islanded mode as a single entity as in the case of microgrids. Instead, they move to islanded mode along with the coupled microgrid, thus meeting the economic and reliability requirements of the less sensitive zones of the distribution system. This work first proposes few new device-based reliability indices for the sustained faults that cater to the new requirements arising due to the presence of distributed generators all over the system, embedded in clusters of microgrids and provisional microgrids. Secondly, considering the occurrences of temporary faults in similar systems, another new load-based reliability index is proposed. Later, for the chosen example distribution system with 69-buses, the existing reliability indices, and the proposed new indices are calculated. At last, the influence of these indices on generation expansion planning problems like placement and sizing of the distributed generators, construction of clusters of microgrids and provisional microgrids, and economic decisions on scheduling of maintenance is discussed in detail.

Research on Construction and Operation of Microgrid

In order to cope with the objective contradiction of the worsening environmental problems and the rigid demand for energy due to the rapid economic development, it is of great significance to explore the technology and management mode of microgrid which is self-used and locally consumed with renewable energy. In this study, on the basis of clarifying the construction goal of microgrid, the energy management system of microgrid is designed, the control mode consistent with the characteristics of renewable energy is selected, the business scope of microgrid is expanded according to the interactive needs of different users, and the intelligent interactive operation of microgrid is realized, which can make better use of renewable energy to meet the rising demand for energy while protecting the environment.

A Bilevel Optimization Model Based on Edge Computing for Microgrid.

With the continuous progress of renewable energy technology and the large-scale construction of microgrids, the architecture of power systems is becoming increasingly complex and huge. In order to achieve efficient and low-delay data processing and meet the needs of smart grid users, emerging smart energy systems are often deployed at the edge of the power grid, and edge computing modules are integrated into the microgrids system, so as to realize the cost-optimal control decision of the microgrids under the condition of load balancing. Therefore, this paper presents a bilevel optimization control model, which is divided into an upper-level optimal control module and a lower-level optimal control module. The purpose of the two-layer optimization modules is to optimize the cost of the power distribution of microgrids. The function of the upper-level optimal control module is to set decision variables for the lower-level module, while the function of the lower-level module is to find the optimal solution by mathematical methods on the basis of the upper-level and then feed back the optimal solution to the upper-layer. The upper-level and lower-level modules affect system decisions together. Finally, the feasibility of the bilevel optimization model is demonstrated by experiments.

An improved method for fault diagnosis of rolling bearings of power generation equipment in a smart microgrid

In the construction of smart microgrids for petrochemical enterprises, the generating unit is an important part, and the rolling bearings are one of the key components of the generator. The condition of the rolling bearing directly affects the safe operation of the entire generating unit and an accurate fault diagnosis of the bearing not only can improve the stability of the smart microgrid, but also can reduce the risk of loss of the factory. This study proposes an improved fault diagnosis method based on variational modal decomposition (VMD) and a convolutional neural network (CNN). The VMD algorithm was used to remove random noise in the original signal and a CNN was used to extract useful data from the vibration signal processed by VMD. Since the modal number and penalty parameter of the VMD are difficult to choose and they have a profound impact on the decomposition results, differential evolution (DE) was used as the optimization method and envelope entropy was used as the fitness function to optimize the VMD parameters. Since it is difficult to ensure the best fit of the hyper-parameters of CNN, this study proposes a method for using the DE algorithm to obtain suitable hyper-parameters for the CNN, and then used the CNN to diagnose a fault. The test results using the vibration data of Case Western Reserve University show that the combination of VMD and CNN can improve the convergence speed more than 10% and the accuracy to over 99.6%.

Providing grid flexibility with sector coupling technologies in Korean distribution system

Recently, world-wide efforts are being made to cope with the global climate crisis. Among many countries, Korean government has set the goal of achieving carbon neutrality by 2050. To this end, as well as increase of renewable energy, system planning, implementation, and research on various measures such as microgrid construction, sector coupling, and Energy Superstation have continued. This paper introduces the methods and analyzes the effects of the Energy Superstation. Simulations are constructed using the charging pattern and electricity consumption pattern of electric vehicles, and the effects on the system are evaluated.

TECHNICAL AND ECONOMIC DEVELOPMENT MECHANISMS OF LOCAL ENERGY SUPPLY SYSTEMS (MICROGRID)

The business model of energy as a service (Energy-as-a-service, EaaS) is considered as a direction of development of the concept of 3D (Decarbonization, Decentralization, Digitalization) and the conceptual model of the Internet of energy. At the same time, EaaS is formed in the form of a "package" service model, in which the customer is provided with hardware and software and energy services. EaaS solutions should include consumption management and energy efficiency services, promote the introduction of renewable energy sources (RES) and other decentralized energy sources, and optimize the balance between supply and demand in the electricity market. EaaS is shown to be a broad term for service-driven business models with innovative potential to transform the energy industry
 To assess the specifics of EaaS application to Microgrid, the construction and operation of Microgrid as a local power system or power supply system, which is a technological complex consisting of generation facilities (energy sources), energy flexibility sources and electricity consumers, which are collected under a single management ensuring the most efficient and consumer-friendly energy supply. It is determined that the technological guarantee of the efficiency of modern Microgrid is the ability to integrate and optimally combine different energy sources and flexibility, as well as the presence of a single control loop that allows the best use of these sources.
 Smart Grid as a Service (SGaaS) based on Service-Oriented Architecture is presented. The SGaaS hierarchical architecture provides a promising three-tier architecture that includes an intelligent network level for global optimization, such as minimizing global protection or global costs, a level of coordination to maintain reliability and security in the Smart Grid, and a Microgrid level to monitor end-user device status.
 The implementation of the EaaS and SGaaS mechanisms has stimulated the development of Microgrid as a Service (MaaS) - as a service that offers the deployment of Microgrid, reducing the initial cost of investment and complexity. MaaS has been identified as a new flagship funding mechanism that allows organizations to deploy Microgrid without any prior investment, as a solution that does not require advance capital for energy consumers and focuses on results such as on-site energy. MaaS mechanisms offer customers more control over their energy needs, enabling them to increase the sustainability and reliability of their energy supply, balance energy use, achieve clean energy goals and explore other innovative products and services.

Looking beyond bill savings to equity in renewable energy microgrid deployment

Microgrids powered by renewable energy can provide backup power to critical infrastructure during grid outages. These systems can also play an important role in advancing energy justice by providing economic, environmental, health, and resilience benefits for underserved communities. The value of microgrids is often measured by the economic savings and resilience provided, but there are other energy justice factors that should be considered. This paper describes a methodology for quantifying broader costs and benefits including utility bill savings, value of resilience, social cost of carbon, public health costs, and jobs associated with the construction and operation of microgrids. We evaluate these factors at three case study sites and find that including energy justice values in the cost-benefit analysis of microgrids can change investment decisions. When climate, health, resilience, and job creation are considered, cost-optimal microgrids include more renewable generation, leading to a 52–82% reduction in emissions and diesel fuel use. The net present values of the microgrids grow from negative $626,000–843,000 in the diesel only case to $10–16 million in the hybrid microgrid case and $12–19 million in the renewable microgrid case, indicating potential for greater microgrid deployment if energy justice values are incorporated in decision making. However, we also see large increases in capital expenses, which could limit deployment unless accompanied by innovative financing measures. These findings may be useful to communities as they seek to strengthen resilience to natural disasters while also improving public health, meeting climate goals, and providing economic opportunity for residents.

Technical Demonstration Related to Microgrid Construction Using Storage Battery System as Main Power Source

Technical Demonstration Related to Microgrid Construction Using Storage Battery System as Main Power Source

ЗАДАЧИ И СТРАТЕГИЯ УПРАВЛЕНИЯ КОНФИГУРАЦИЕЙ СЕЛЬСКОЙ МИКРОСЕТИ, СОДЕРЖАЩЕЙ ВОЗОБНОВЛЯЕМЫЕ ИСТОЧНИКИ ЭНЕРГИИ

A significant disadvantage of rural distribution electric grids of 0.4 kV is the lack of the ability to operate their configuration. This disadvantage leads to a decrease in the reliability of electricity supply and significant damage to rural consumers from interruptions in electricity supply. A promising direction is the introduction of distributed generation based on renewable energy sources (RES), electricity storage devices into the structure of rural electric grids and the construction of microgrids based on them. However, the issues of building rural microgrids have not been worked out today, the search for rational options for their structure is being conducted all over the world, the development of equipment for their construction is underway. Therefore, the purpose of the research presented in the article is to determine the tasks and strategies for operating the configuration of rural microgrids containing renewable energy sources (RES) based on the use of means of partitioning and reserving the electric grid, that is, means of controlling its configuration and means of monitoring the parameters of its operation modes. As a means of partitioning and reserving the electric grid, it is proposed to use multi-contact switching systems installed at the points of branches in the grid and equipped with sensors for the parameters of the grid operating modes. The use of multi-contact switching systems allows you to implement a flexible change in the grid configuration when changing its operating modes. Power supply sources are also equipped with sensors. The data from the sensors is transmitted to the virtual power plant, which monitors the operating modes of the grid and forms commands for controlling its configuration. This allows you to monitor the operating modes of grid sections and power supply sources, identify normal, emergency and post-emergency modes and make the necessary changes to the grid configuration in a timely manner. As a strategy for the operation of an electrical grid containing renewable energy sources and configuration operating tools, a strategy is proposed that assumes the maximum use of the energy generated by renewable sources when the restrictions are met – a given level of reliability of power supply to consumers and the quality of electricity supplied to them

A new design of control & power management strategies of hybrid ac-dc microgrids toward high power quality

The micro grid idea provides for the lack of several reversing switches to unitary AC-DC grid that enables connection and charges (loads) to the electrical systems with changeable regenerative AC and CC sources. Safe operation and gadget safety involve digital integration with utilities/grid through power converters. Enhanced client reliability, decreased input losses, local voltages are supported, and waste heat efficiency increased, voltage drop or interruptible supply of electricity can be customized to satisfy their unique customer demands. Work at present Analyses the performance in grid tie mode of hybrid AC/DC systems. Here are PV systems, PV systems, For the construction of microgrids wind turbine generators and batteries are employed. Convert procedures for the correct coordination of AC sub-grids to DC subs-grids have also been established for converters. MATLAB/SIMULINK environment results are generated.

Peer-to-Peer energy trading in a microgrid based on iterative double auction and blockchain

The research and construction of microgrids provide the possibility of effective use of distributed energy resources (DERs), where electricity is generated and consumed locally. Peer-to-Peer (P2P) energy trading in microgrids helps to create a totally competitive and autonomous market and brings benefits to both the market participants and utility companies. A P2P energy trading model based on iterative double auction and blockchain is proposed in this paper. The iterative double auction mechanism is used to elicit hidden information from all participants to achieve maximum social welfare, where buyers and sellers adjust quotes to better individual profits according to previous individual transaction volumes and the market equilibrium price, without much knowledge about the market itself. The optimal allocation of the energy and market equilibrium is obtained and verified. The autonomous realization of this P2P energy trading model on blockchain is further presented and discussed. Numerical examples are used to illustrate the feasibility and validity of the proposed iterative double auction algorithm. It is found that the average hourly social welfare for the proposed iterative double auction algorithm is − $29.06, which is a 22.3% increase over the zero-intelligence strategy ( − $37.41).