Distributed Energy Systems and Resources

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Electricity electricity	-	4.8	2020	27.2 Days	CHF 1000
Energies energies	3.0	6.2	2008	17.5 Days	CHF 2600
Resources resources	3.6	7.2	2012	33.4 Days	CHF 1600
Sustainability sustainability	3.3	6.8	2009	20 Days	CHF 2400
Electronics electronics	2.6	5.3	2012	16.8 Days	CHF 2400

14 pages, 3389 KiB

Open AccessArticle

Romanian Energy System Analysis (Production, Consumption, and Distribution)

by Michael Fratita, Florin Popescu, Eugen Rusu, Ion V. Ion and Răzvan Mahu

Energies 2023, 16(16), 6045; https://doi.org/10.3390/en16166045 - 18 Aug 2023

Viewed by 1746

The aim of this paper is to provide a comprehensive overview of how electricity is produced from different sources and the electricity needs of the consumer. According to the Green Deal pact, the objective is to gradually reduce polluting emissions in the energy [...] Read more.

The aim of this paper is to provide a comprehensive overview of how electricity is produced from different sources and the electricity needs of the consumer. According to the Green Deal pact, the objective is to gradually reduce polluting emissions in the energy sector by 2050. In the meantime, the CO₂ intensive thermal power plants (those using coal and heavy oil) will be closed and strategic investments in green energy sources will be pursued. This paper presents a detailed analysis of the profile of the Romanian electricity producer over a period of one year. Furthermore, this paper explores the possibility for the energy producer to adapt to consumer demand to reduce electricity imports, strategic locations for the installation of farms using renewable energy, and the current capacity of the national distribution system. This paper analyses electricity only quantitatively and not qualitatively, as well as the way the supplier follows consumers’ need. The paper concludes on possible problems that may arise from the case of green energy. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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13 pages, 3254 KiB

Open AccessArticle

Cluster Partition-Based Voltage Control Combined Day-Ahead Scheduling and Real-Time Control for Distribution Networks

by Wenwen Sun and Guoqing He

Energies 2023, 16(11), 4375; https://doi.org/10.3390/en16114375 - 27 May 2023

Cited by 2 | Viewed by 1392

Abstract

Considering the possible overvoltage caused by high-penetration photovoltaics (PVs) connected to the distribution networks (DNs), a cluster partition-based voltage control combined day-ahead scheduling and real-time control for distribution networks is proposed. Firstly, a community detection algorithm utilizing a coupling quality function is introduced [...] Read more.

Considering the possible overvoltage caused by high-penetration photovoltaics (PVs) connected to the distribution networks (DNs), a cluster partition-based voltage control combined day-ahead scheduling and real-time control for distribution networks is proposed. Firstly, a community detection algorithm utilizing a coupling quality function is introduced to divide the PVs into clusters. Based on the cluster partition, day-ahead scheduling (DAS) is proposed with the objective of minimizing the operating costs of PVs, as well as the on-load tap changer (OLTC). In the real-time control, a second-order cone programming (SOCP) model-based real-time voltage control (RTVC) strategy is drawn up in each cluster to regulate the PV inverters, and this strategy can correct the day-ahead scheduling by modifications. The proposed strategy realizes the combination of day-ahead scheduling and real-time voltage control, and the optimization of voltage control can be greatly simplified. Finally, the proposed method is applied to a practical 10 kV feeder to verify its effectiveness. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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15 pages, 1318 KiB

Open AccessArticle

The Role of Distributed Energy Resources and Associated Business Models in the Decentralised Energy Transition: A Review

by Karlson Hargroves, Benjamin James, Joshua Lane and Peter Newman

Energies 2023, 16(10), 4231; https://doi.org/10.3390/en16104231 - 21 May 2023

Cited by 9 | Viewed by 13321

Abstract

The shift from large-scale centralised energy systems to smaller scale decentralised systems based on Distributed Energy Resources (DER) is likely to cause a sector-wide replacement of current electricity management practices and business models—creating a new energy paradigm. If handled well, such a transition [...] Read more.

The shift from large-scale centralised energy systems to smaller scale decentralised systems based on Distributed Energy Resources (DER) is likely to cause a sector-wide replacement of current electricity management practices and business models—creating a new energy paradigm. If handled well, such a transition will not be inherently disruptive; however, it can cause major disruption if long-held views and assumptions are not rapidly reconsidered and renewed, and new supporting structures are not swiftly put in place—hence, if disruption is experienced it will be due to a lack of strategic responses rather than the nature of the technology. This paper clarifies the nature of DERs and outlines key issues and opportunities associated with a range of associated service configurations and business models. The paper outlines key factors affecting the viability of such approaches and identifies leverage points for accelerating uptake. The paper concludes by considering how shifting landscape factors and related opportunities in the coming decades will shape the transition to a decentralised energy system. This paper contains findings from research performed at the Renewable, Affordable, Clean Energy Cooperative Research Centre (RACE CRC) in Australia. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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17 pages, 6818 KiB

Open AccessArticle

Hosting Capacity Estimate Based on Photovoltaic Distributed Generation Deployment: A Case Study in a Campus of the University of São Paulo

by Igor Cordeiro, Welson Bassi and Ildo Luís Sauer

Energies 2023, 16(9), 3934; https://doi.org/10.3390/en16093934 - 6 May 2023

Cited by 3 | Viewed by 2851

Abstract

Distributed generation, which is mainly deployed with PV systems that benefit economically prosumers, has soared in use in Brazil. Despite this, PV capacity in excess may cause technical issues which concern planning engineers who have adopted rules of thumb to screen interconnection requests [...] Read more.

Distributed generation, which is mainly deployed with PV systems that benefit economically prosumers, has soared in use in Brazil. Despite this, PV capacity in excess may cause technical issues which concern planning engineers who have adopted rules of thumb to screen interconnection requests without any detailed study. Recently, the hosting capacity concept has been employed to assess how much PV capacity a distribution grid can host without deteriorating grid parameters, reliability, or power quality. A steady-state and worst-case-based scenario was used to run deterministic power flow simulations to estimate the hosting capacity of a specific radial circuit at a campus of the University of São Paulo, referred to as “USP-105”. Although the result may be not completely accurate, it was found that USP-105 can accommodate 103% of its peak load or 4970.6 kW of PV power, which reduced the circuit’s annual peak load by 9%. Another finding was that hosting capacity increased when PV-DG deployment was dispersed along the circuit rather than concentrated on a single location (e.g., closest, or furthest to the substation). Utilities may therefore benefit from a simple and quick assessment to obtain an overview of how specific circuits behave on PV deployment and indicate which locations are technically more beneficial. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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16 pages, 3909 KiB

Open AccessArticle

Multiple Virtual Power Plants Transaction Matching Strategy Based on Alliance Blockchain

by Tianfeng Chu, Xingchen An, Wuyang Zhang, Yan Lu and Jiaqi Tian

Sustainability 2023, 15(8), 6939; https://doi.org/10.3390/su15086939 - 20 Apr 2023

Cited by 9 | Viewed by 1777

Abstract

Virtual power plants can aggregate distributed energy resources and interruptible loads in a region for coordinated regulation and unified transaction. However, with the diversification of competition in the electricity market, the distributed operation mechanism between multiple virtual power plants (multi-VPPs) has gradually become [...] Read more.

Virtual power plants can aggregate distributed energy resources and interruptible loads in a region for coordinated regulation and unified transaction. However, with the diversification of competition in the electricity market, the distributed operation mechanism between multiple virtual power plants (multi-VPPs) has gradually become a research focus. Based on this, this paper proposes a new type of distributed transactions strategy between multi-VPPs, i.e., the transaction matching mechanism. A two-stage transaction model based on the transaction matching is constructed for multi-VPPs to participate in the day-ahead and intraday electricity trading markets. In the first stage, each VPP optimizes its own internal units’ output and external interaction power through a cooperative game; in the second stage, it is the transaction matching among multi-VPPs that can match the most suitable counterpart by flexible price setting to increase the benefits of all the VPPs. Considering the efficiency and security of blockchain technology, we choose to complete the transaction matching between multi-VPPs with the support of alliance blockchain technology to improve the speed of system solution. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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19 pages, 296 KiB

Open AccessArticle

Willingness-to-Pay of Converting a Centralized Power Generation to a Distributed Power Generation: Estimating the Avoidance Benefits from Electric Power Transmission

by Sungwook Yoon

Sustainability 2023, 15(6), 4949; https://doi.org/10.3390/su15064949 - 10 Mar 2023

Viewed by 1060

Abstract

Centralized power generation has been widely used for power generation due to its high efficiency, but its transmission and distribution facilities have caused a lot of economic and social costs. The distributed power generation, which produces electricity distributed around consumers without large transmission [...] Read more.

Centralized power generation has been widely used for power generation due to its high efficiency, but its transmission and distribution facilities have caused a lot of economic and social costs. The distributed power generation, which produces electricity distributed around consumers without large transmission facilities, has emerged as an alternative. This study aims to derive the social costs and damage avoidance benefits of converting centralized into distributed power generation through willingness-to-pay (WTP) and find determinants that affect them. The economic and social damage caused by centralized power generation facilities is categorized into four types of damage, and the WTP for each type of damage is elicited using various types of quantitative, machine-learning models. Results show that people perceive health damage relief as the greatest benefit of the avoidance of centralized power generation facilities, and it accounted for 29~51% of the total WTP. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

19 pages, 5438 KiB

Open AccessArticle

Optimal SOFC-CHP Installation Planning and Operation Model Considering Geographic Characteristics of Energy Supply Infrastructure

by Takashi Owaku, Hiromi Yamamoto and Atsushi Akisawa

Energies 2023, 16(5), 2236; https://doi.org/10.3390/en16052236 - 25 Feb 2023

Cited by 1 | Viewed by 1636

Abstract

Combined heat and power (CHP) is crucial for promoting thorough energy conservation and advanced energy use, aimed toward greenhouse gas reduction. Solid oxide fuel cell (SOFC)-CHP is expected to be introduced as a measure against global warming and has been the focus of [...] Read more.

Combined heat and power (CHP) is crucial for promoting thorough energy conservation and advanced energy use, aimed toward greenhouse gas reduction. Solid oxide fuel cell (SOFC)-CHP is expected to be introduced as a measure against global warming and has been the focus of attention, and this study examined the effects of its introduction. This study introduces a linear programming evaluation model that can simulate optimized facility configuration and operation, based on the power supply and demand. The novelty of the proposed model is the consideration of geographic characteristics, which influences parameters dependent on gas transportation infrastructure and electricity. A sensitivity analysis was conducted considering the number of units and location of SOFC-CHP introductions in the National Capital Region of Japan. As a result, it was predicted that SOFC-CHP would likely begin to be introduced in areas where there is a large shadow price difference between electricity and gas at each node. The total power generation will decrease, as transmission and distribution losses decrease, owing to the diffusion of SOFC-CHP installed in the vicinity of demand. The widespread use of SOFC-CHP is an economically feasible CO₂ emissions reduction pathway. These results will help assess the introduction of various distributed power sources in addition to SOFC-CHP to reduce CO₂ emissions. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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15 pages, 1748 KiB

Open AccessArticle

Multi-Period Transmission Expansion Planning for Renewables-Rich Power Grid Enabling Transfer Capacity Enhancement of Hybrid AC/DC Interface

by Li Shen, Li Jiang, Qing Wang, Yiyu Wen and Tingjian Liu

Energies 2023, 16(5), 2170; https://doi.org/10.3390/en16052170 - 23 Feb 2023

Cited by 1 | Viewed by 1579

Abstract

With the increasing integration of HVDC tie-lines, the regional power systems in both the energy-exporting area and the energy-importing area have been gradually evolving into “strong DC, weak AC” systems. In this paper, a multi-period transmission expansion planning optimization model is proposed for [...] Read more.

With the increasing integration of HVDC tie-lines, the regional power systems in both the energy-exporting area and the energy-importing area have been gradually evolving into “strong DC, weak AC” systems. In this paper, a multi-period transmission expansion planning optimization model is proposed for an energy-exporting power grid with hybrid AC/DC interface. While the existing literature has not considered the dynamic security problem in TEP, this paper adopts the conventional total transfer capacity (TTC) index to evaluate the security limit of hybrid AC/DC interface under different transmission expansion schemes. Multiple objectives are considered to reduce the investment cost while promoting the consumption of renewables by enhancing the total transfer capacity of hybrid AC/DC interface. The non-dominated sorting genetic algorithm-II (NSGA-II) is used to compute the optimal solution for the proposed multi-period multi-objective transmission expansion planning problem. A case study on the modified IEEE 39-bus system is presented to demonstrate the effectiveness of the proposed method. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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20 pages, 9431 KiB

Open AccessArticle

Adaptive Double Kalman Filter Method for Smoothing Wind Power in Multi-Type Energy Storage System

by Lei Qin, Na Sun and Haiying Dong

Energies 2023, 16(4), 1856; https://doi.org/10.3390/en16041856 - 13 Feb 2023

Cited by 7 | Viewed by 1900

Abstract

At present, in the situation that wind power penetration is increasing year by year, the use of a hybrid energy storage system (HESS) to smooth out wind power fluctuations becomes an effective method. However, the existing control strategy has the problem of inadequate [...] Read more.

At present, in the situation that wind power penetration is increasing year by year, the use of a hybrid energy storage system (HESS) to smooth out wind power fluctuations becomes an effective method. However, the existing control strategy has the problem of inadequate utilization of fluctuating power. In this paper, we propose a control strategy for smoothing wind power fluctuations based on double Kalman filters with adaptive adjustment of the state of charge (SOC). Firstly, considering the wind power’s active power grid constraint, the parameters of the dual Kalman filter are adaptively adjusted according to the original output power to obtain the target grid power synchronously, and the total smoothing command of the energy storage system is determined with the goal of improving the SOC of the lithium battery. On this basis, the SOC of the supercapacitor is considered to be improved, and the adaptive low-pass filter is used for the secondary distribution of the energy storage power command to achieve fine-grained management of the output power of HESS. The final simulation results show that the obtained smoothed wind power satisfies the 1 min and 10 min fluctuation criteria, and the minimum capacity required for lithium batteries is reduced by 0.07 MW·h under the same initial conditions as in the proposed method in this paper; it can use the fluctuating power when the SOC crosses the limit, and has a regulating effect on the SOC of HESS to improve the wind power smoothing ability and realize the stable grid-connection requirement of wind power. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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15 pages, 3177 KiB

Open AccessArticle

A Bi-Level Optimization Model for Virtual Power Plant Membership Selection Considering Load Time Series

by Yantao Wang, Yinhan Zhang, Xuesong Qi, Meiqi Wang and Xinyue Wang

Sustainability 2023, 15(3), 2138; https://doi.org/10.3390/su15032138 - 23 Jan 2023

Cited by 4 | Viewed by 1779

Abstract

In order to improve the level of new energy consumption and reduce the dependence of the power system on traditional fossil energy, this paper proposed a bi-level optimization model for virtual power plant member selection by means of coordination and complementarity among different [...] Read more.

In order to improve the level of new energy consumption and reduce the dependence of the power system on traditional fossil energy, this paper proposed a bi-level optimization model for virtual power plant member selection by means of coordination and complementarity among different power sources, aiming at optimizing system economy and clean energy consumption capacity and combining it with the time sequence of load power consumption. The method comprises the following steps: (1) The processing load, wind power, and photovoltaic data by using ordered clustering to reflect the time sequence correlation between new energy and load and (2) uses a double-layer optimization model, wherein the upper layer calculates the capacity configuration of thermal power and energy storage units in a virtual power plant and selects the new energy units to participate in dispatching by considering the utility coefficient of the new energy units and the environmental benefit of the thermal power units. The Latin hypercube sampling (LHS) method was used to generate a large number of subsequences and the mixed integer linear programming (MILP) algorithm was used to calculate the optimal operation scheme of the system. The simulation results showed that by reducing the combination of subsequences between units and establishing a reasonable unit capacity allocation model, the average daily VPP revenue increased by RMB 12,806 and the proportion of new energy generation increased by 1.8% on average, which verified the correctness of the proposed method. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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15 pages, 294 KiB

Open AccessReview

Optimal Scheduling of Controllable Resources in Energy Communities: An Overview of the Optimization Approaches

by Emely Cruz-De-Jesús, Jose L. Martínez-Ramos and Alejandro Marano-Marcolini

Energies 2023, 16(1), 101; https://doi.org/10.3390/en16010101 - 22 Dec 2022

Cited by 8 | Viewed by 2153

Abstract

In recent years, there has been a growing interest in the study of energy communities. This new definition refers to a community sharing energy resources of different types to meet its needs and reduce the associated costs. Optimization is one of the most [...] Read more.

In recent years, there has been a growing interest in the study of energy communities. This new definition refers to a community sharing energy resources of different types to meet its needs and reduce the associated costs. Optimization is one of the most widely used techniques for scheduling the operation of an energy community. In this study, we extensively reviewed the mathematical models used depending on the objectives and constraints considered. The models were also classified according to whether they address uncertainty and the inclusion of flexibility constraints. The main contribution of this study is the analysis of the most recent research on the mathematical formulation of optimization models for optimal scheduling of resources in energy communities. The results show that the most commonly used objectives are profit maximization and cost minimization. Additionally, in almost all cases, photovoltaic generation is one of the main energy sources. Electricity prices, renewable generation, and energy demand are sources of uncertainty that have been modeled using stochastic and robust optimization. Flexibility services using demand response are often modeled using interruptible loads and shiftable loads. There is still considerable room for further research on the distribution of benefits among the participants of the energy community and the provision of flexibility services to the electricity grid. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

21 pages, 4653 KiB

Open AccessArticle

Distributionally Robust Unit Commitment with N-k Security Criterion and Operational Flexibility of CSP

by Younan Pei, Xueshan Han, Pingfeng Ye, Yumin Zhang, Mingbing Li and Huizong Mao

Energies 2022, 15(23), 9202; https://doi.org/10.3390/en15239202 - 5 Dec 2022

Viewed by 1455

Abstract

In order to reduce the conservatism of the robust optimization method and the complexity of the stochastic optimization method and to enhance the ability of power systems to deal with occasional line fault disturbance, this paper proposes a distributionally robust unit commitment (DRUC) [...] Read more.

In order to reduce the conservatism of the robust optimization method and the complexity of the stochastic optimization method and to enhance the ability of power systems to deal with occasional line fault disturbance, this paper proposes a distributionally robust unit commitment (DRUC) model with concentrating solar power (CSP) operational flexibility and N-k safety criterion under distributed uncertainty. According to the limited historical sample data, under the condition of satisfying a certain confidence level, based on the imprecise Dirichlet model (IDM), an ambiguity set is constructed to describe the uncertainty of transmission line fault probability. Through the identification of the worst probability distribution in the ambiguity set, the adaptive robust optimal scheduling problem is transformed into a two-stage robust optimization decision model under the condition of deterministic probability distribution. The CSP flexibility column and constraint generation (C&CG) algorithm is used to process the model and the main problem and subproblem are solved by using the Big-M method, linearization technique, and duality principle. Then, a mixed integer linear programming problem (MILP) model is obtained, which effectively reduces the difficulty of solving the model. Finally, case studies on the IEEE 14 bus system and the IEEE 118 bus system demonstrate the efficiency of the proposed method, such as enhancing the ability of power systems to cope with occasional line fault disturbances and reducing the conservatism of the robust optimization method. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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17 pages, 4185 KiB

Open AccessArticle

Power-to-Methane to Integrate Renewable Generation in Urban Energy Districts

by Gianluigi Lo Basso, Lorenzo Mario Pastore and Livio de Santoli

Energies 2022, 15(23), 9150; https://doi.org/10.3390/en15239150 - 2 Dec 2022

Cited by 9 | Viewed by 1697

Abstract

The deployment of distributed energy systems must take place paying attention to the self-consumption of renewable generation. Innovative sector coupling strategies can play that role linking local electricity and gas grids. The present work aims to evaluate the energy and economic feasibility of [...] Read more.

The deployment of distributed energy systems must take place paying attention to the self-consumption of renewable generation. Innovative sector coupling strategies can play that role linking local electricity and gas grids. The present work aims to evaluate the energy and economic feasibility of the Power-to-Methane strategy application in urban energy districts. A residential cluster was considered as a case study. Two PV configurations have been applied to evaluate the Substitute Natural Gas (SNG) production under different renewable excess conditions. Thereafter, the Power-to-Methane strategy was implemented by varying the system’s size. Some significant configurations have been compared to each other in terms of energy and economics. Beyond a certain threshold limit, an increase in the photovoltaic size slightly enhances the effectively self-consumed energy. The Power-to-Methane strategy can exploit all the renewable excess once the system is properly sized, almost doubling the potential energy consumption reduction compared to the PV system alone. The SNG production cost is between 100 and 200 EUR/MWh in most configurations, which is competitive with the high natural gas prices on the European market. Therefore, decentralised SNG production can reduce the households’ annual expenditures and it can mitigate the energy poverty conditions over the current energy crisis period. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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26 pages, 6279 KiB

Open AccessReview

Grid-Forming Virtual Power Plants: Concepts, Technologies and Advantages

by Khalil Gholami, Behnaz Behi, Ali Arefi and Philip Jennings

Energies 2022, 15(23), 9049; https://doi.org/10.3390/en15239049 - 29 Nov 2022

Cited by 3 | Viewed by 2814

Abstract

Virtual Power Plants (VPPs) are efficient structures for attracting private investment, increasing the penetration of renewable energy and reducing the cost of electricity for consumers. It is expected that the number of VPPs will increase rapidly as their financial return is attractive to [...] Read more.

Virtual Power Plants (VPPs) are efficient structures for attracting private investment, increasing the penetration of renewable energy and reducing the cost of electricity for consumers. It is expected that the number of VPPs will increase rapidly as their financial return is attractive to investors. VPPs will provide added value to consumers, to power systems and to electricity markets by contributing to different services such as the energy and load-following services. One of the capabilities that will become critical in the near future, when large power plants are retired, is grid-forming capability. This review paper introduces the concept of grid-forming VPPs along with their corresponding technologies and their advantages for the new generation of power systems with many connected VPPs. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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21 pages, 23898 KiB

Open AccessArticle

A Virtual Inertia Method for Stability Control of DC Distribution Systems with Parallel Converters

by Qun Gao, Yan Jiang, Ke Peng and Lei Liu

Energies 2022, 15(22), 8581; https://doi.org/10.3390/en15228581 - 16 Nov 2022

Cited by 1 | Viewed by 1342

Abstract

DC distribution systems are a typical power electronic system with low inertia, low-rotational kinetic energy, and poor antidisturbance capability when loads fluctuate or parameters change. In this paper, a virtual inertia control with an additional first-order filtering link is proposed on the basis [...] Read more.

DC distribution systems are a typical power electronic system with low inertia, low-rotational kinetic energy, and poor antidisturbance capability when loads fluctuate or parameters change. In this paper, a virtual inertia control with an additional first-order filtering link is proposed on the basis of P-U_dc droop control. The results of the simulations and experiments verify that the additional inertia control reduces the voltage change rate and improves the system inertia by adjusting the virtual capacitance value on the DC side of the converter, which can achieve a smoother and more accurate voltage control and suppress the continuous voltage oscillation. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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18 pages, 3132 KiB

Open AccessArticle

Research on Current Distribution Strategy Based on Interleaved Double Boost Converter

by Pengcheng Wang, Chengchen Li, Junqi Liu, Xingchen Cao, Haoran Cui, Yi Zhang and Rui Wang

Sustainability 2022, 14(22), 14797; https://doi.org/10.3390/su142214797 - 9 Nov 2022

Cited by 1 | Viewed by 1560

Abstract

In the new energy DC microgrid system, most of the new energy outputs DC power with a low voltage level and a large fluctuation range, which cannot be directly connected to the network. It needs to be boosted by a DC–DC converter, then [...] Read more.

In the new energy DC microgrid system, most of the new energy outputs DC power with a low voltage level and a large fluctuation range, which cannot be directly connected to the network. It needs to be boosted by a DC–DC converter, then connected to the power grid or supplied with a DC load. On the premise that the traditional DC–DC converter cannot meet the requirements of high-power applications, the interleaved dual boost converter (IDBC) has been widely used because of its low input current ripple, low device stress and high-power density. It is necessary to maintain the current balance of each phase of the converter during a heavy load and to improve the efficiency during a light load. This paper analyzes the working principle of the six-phase IDBC and reduces the high order model to the low order model according to the symmetry. Due to the current imbalance caused by the mismatch of the parasitic parameters of each phase, two current distribution strategies are designed for different operating. To balance the current of each phase when the converter is overloaded, the relationship between the phase current, parasitic parameters and duty cycle is analyzed based on the state space average method. The estimated parasitic parameters are used to obtain the duty cycle compensation of each phase to eliminate the current imbalance. In addition, to improve the overall efficiency of the converter when the converter connects with a light load, the optimal power distribution coefficient is obtained according to the parasitic parameters to achieve the optimization of the input power, so as to improve the efficiency of the converter. Finally, the simulation results verify the feasibility and effectiveness of the proposed control strategy. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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16 pages, 1893 KiB

Open AccessArticle

Dynamic Economic Dispatching Considering Time-Coupling Spinning Reserve Response Risk with High Penetration of Wind Power

by Younan Pei, Xueshan Han, Pingfeng Ye, Yumin Zhang and Lihong Zhang

Energies 2022, 15(21), 7831; https://doi.org/10.3390/en15217831 - 22 Oct 2022

Cited by 1 | Viewed by 1364

Abstract

Aiming at the problem that the current dynamic economic dispatch (DED) fails to consider the response risk of spinning reserve caused by the fluctuation and uncertainty of wind power, we work out a DED problem considering time-coupling spinning reserve response risk while the [...] Read more.

Aiming at the problem that the current dynamic economic dispatch (DED) fails to consider the response risk of spinning reserve caused by the fluctuation and uncertainty of wind power, we work out a DED problem considering time-coupling spinning reserve response risk while the stochasticity and variability arising from RESs are taken into consideration. The developed framwork unified the response risk of reserve caused by forced shutdown of the unit into the response risk caused by time coupling. The expected customer interruption cost (ECOST) and the expected abandoned wind cost considering this reserve response risk are added to the objective function. While seeking the minimum objective function, the system is automatically configured with suitable reserve to ensure the consistency of the system’s response risk in each period. An improved multi-universe parallel quantum genetic algorithm was used to solve the model. Numerical examples and analysis prove the effectiveness and feasibility of the proposed method. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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24 pages, 9513 KiB

Open AccessArticle

Technical, Economic, and Intelligent Optimization for the Optimal Sizing of a Hybrid Renewable Energy System with a Multi Storage System on Remote Island in Tunisia

by Mohamed Hajjaji, Dhafer Mezghani, Christian Cristofari and Abdelkader Mami

Electronics 2022, 11(20), 3261; https://doi.org/10.3390/electronics11203261 - 11 Oct 2022

Cited by 6 | Viewed by 2581

Abstract

Due to their small dimension and isolated energy systems, islands face a significant energy supply challenge. In general, they use fossil fuels for electricity generation. Fossil fuels are a major source of CO2 emissions, and they are very costly. The cost of electricity [...] Read more.

Due to their small dimension and isolated energy systems, islands face a significant energy supply challenge. In general, they use fossil fuels for electricity generation. Fossil fuels are a major source of CO2 emissions, and they are very costly. The cost of electricity generation on islands is up to 10 times higher than on the mainland. This situation without a doubt represents a financial burden for the islanders. Using renewable sources, especially solar and wind sources, offers great potential for power generation in remote locations, as they are a clean and inexhaustible source of energy. Electrifying these zones with a hybrid system consisting of a photovoltaic (PV) and wind systems associated to a hydraulic and an electrochemical storage system is a promising alternative. The purpose of this study is to optimize the dimension of the components generation of systems, especially for a remote island in Tunisia. The first part of this object outlines the PV-wind-battery-hydraulic generation system architecture and modeling. The optimal sizing of the device additives, satisfying two criteria with the aid of evolutionary algorithms NSGAII, is defined inside the second part of this article. The outcomes are discussed from the point of view of the importance of the system dimension and in terms of compliance with the criteria through the study of the most optimal particular configurations. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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16 pages, 5834 KiB

Open AccessArticle

An Adaptive Switching Control Strategy under Heavy–Light Load for the Bidirectional LLC Considering Parasitic Capacitance

by Yetong Han, Rui Wang, Yi Zhang, Dazhong Ma, Shaoxv Jiang and Liangwu Wen

Sustainability 2022, 14(19), 11832; https://doi.org/10.3390/su141911832 - 20 Sep 2022

Cited by 1 | Viewed by 1393

Abstract

The LLC topology is widely used to link renewable energy and inverters to provide constant voltage in the smart grid. Due to its characteristics, the voltage regulation range under light load conditions is limited, so that the output voltage cannot be maintained constant. [...] Read more.

The LLC topology is widely used to link renewable energy and inverters to provide constant voltage in the smart grid. Due to its characteristics, the voltage regulation range under light load conditions is limited, so that the output voltage cannot be maintained constant. The adaptive switching control strategy is proposed in this paper to keep the output constant. Under heavy load conditions, the voltage is kept constant by adjusting the frequency to ensure the accuracy of the control. The phase shift is adjusted to achieve constant voltage, considering the influence of parasitic capacitance on the modeling process for the changing trend of output voltage in light load conditions. The switching point is calculated from the characteristic curve to ensure that the output voltage is stable during mode switching. In addition, there is a new hysteresis control which is robust near the switching point to cope with the instability of the new energy itself and frequent disturbance under light load. Finally, a 400V–36V–1KW prototype is used to verify this control strategy. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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26 pages, 6665 KiB

Open AccessReview

Overview of the Role of Energy Resources in Algeria’s Energy Transition

by Youcef Himri, Shafiqur Rehman, Ali Mostafaeipour, Saliha Himri, Adel Mellit, Mustapha Merzouk and Nachida Kasbadji Merzouk

Energies 2022, 15(13), 4731; https://doi.org/10.3390/en15134731 - 28 Jun 2022

Cited by 15 | Viewed by 4881

Abstract

Algeria is a wealthy country with natural resources, namely, nuclear, renewable, and non-renewable sources. The non-renewable energy sources are considered the lion’s share for energy production (98%). Algeria’s efforts to ensure and strengthen its energy security will take an important step in the [...] Read more.

Algeria is a wealthy country with natural resources, namely, nuclear, renewable, and non-renewable sources. The non-renewable energy sources are considered the lion’s share for energy production (98%). Algeria’s efforts to ensure and strengthen its energy security will take an important step in the coming decades by commissioning new energy infrastructure based on intensive use of water, coal, nuclear, non-renewable, and renewable sources. The implementation of new power infrastructure is expected to be operational from 2030. The renewable power realization in Algeria is relatively less compared to other African countries, i.e., Morocco, Egypt, South Africa, etc. The total renewable power installed capacity in Algeria reached 686 MW in 2020, as part of its national energy portfolio, although the Algerian government has spent tremendous efforts on introducing new sustainable technologies to enable the transition towards a cleaner and sustainable energy system. Indeed, the country announced its plan to install around 22 GW of renewable energy capacity by 2030. It will include 1 GW bio-power from the waste, 13.5 GW from solar PV, 2 GW from CSP, 15 MW from geothermal, 400 MW cogeneration, and, finally, 5 GW from wind. The scope of the present research provides general information about the usage of energy resources such as fossil, nuclear, and renewable sources in Algeria and also covers the energy supply outlook. The present effort is the first of its kind which discusses the application of the coal and nuclear as clean energy sources as part of renewable energy transition. Additionally, it also includes the description of the existing Algerian energy sector and information about water and water desalination and their usage in other sectors. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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25 pages, 2565 KiB

Open AccessArticle

Simulation Analysis of a Double Auction-Based Local Energy Market in Socio-Economic Context

by Steven Beattie, Wai-Kin (Victor) Chan, Zixuan Wei and Zhibin Zhu

Sustainability 2022, 14(13), 7642; https://doi.org/10.3390/su14137642 - 23 Jun 2022

Cited by 1 | Viewed by 1906

Abstract

Local energy markets (LEMs) use online platforms and smart grid technologies to incentivize and coordinate a local supply of spatially-distributed renewable energy resources, which may not be directly controllable by power system operators. Socio-economic values are increasingly noted as prominent motivations for expected [...] Read more.

Local energy markets (LEMs) use online platforms and smart grid technologies to incentivize and coordinate a local supply of spatially-distributed renewable energy resources, which may not be directly controllable by power system operators. Socio-economic values are increasingly noted as prominent motivations for expected LEM users, but socio-economic aspects of user decision-making or market outcomes are not considered in current LEM mechanism design analyses. Here, agent-based simulation is used to analyze expected socio-economic outcomes from LEM operation under a double-sided auction with uniform pricing. The environment is modeled as a virtual LEM platform, operating independently from the underlying power grid. Socio-economic market inputs are produced by income-preference heterogeneous agents, and market outcomes are evaluated by two key socio-economic metrics: energy affordability, and market access. When LEM prices are not restricted to a common range considered by all agents (e.g., between external retail market prices), access disparities may arise; LEM price restriction addresses consumer disparities, but energy affordability gaps are expected to remain. The magnitude of affordability gaps is notably reduced, and bill assistance programs may eliminate remaining gaps, but a mechanism that efficiently realizes socio-economic standards for energy affordability may also reduce expected LEM operation costs. Remaining research gaps are noted, and LEM support for equitable and sustainable energy infrastructure is emphasized. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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21 pages, 5446 KiB

Open AccessArticle

Methodology for Evaluating Projects Aimed at Service Quality Using Artificial Intelligence Techniques

by Bruno José Sampaio de Sousa and Juan Moises Mauricio Villanueva

Energies 2022, 15(13), 4564; https://doi.org/10.3390/en15134564 - 22 Jun 2022

Cited by 2 | Viewed by 1591

Abstract

The quality of the electrical energy distribution service has a significant impact on consumer satisfaction and the guarantee of the right of concession for the distribution companies. For the utility that is the object of the case study, the main continuity of service [...] Read more.

The quality of the electrical energy distribution service has a significant impact on consumer satisfaction and the guarantee of the right of concession for the distribution companies. For the utility that is the object of the case study, the main continuity of service indicators was at levels below the regulatory limits. Still, due to budget constraints, the forecast of the benefit that improvement or expansion projects bring to continuity indicators must be assertive for a proper direction of investments and decision making. In this work, a methodology for evaluating projects to improve the quality of service was proposed, with the realization of the estimated benefit associated with the reduction in continuity indicators (DEC and FEC), using concepts of artificial neural networks and evolutionary algorithms. The results were obtained from a three-year history of execution of the utility’s projects. Based on the correlation analysis, a variable selection procedure was developed, where the historical values of interruptions by cause were considered as input, and the results of the continuity indicators associated with the types of projects studied form the outputs of the model. The model was developed using an artificial neural network of the multilayer perceptron type. The results obtained by simulating the new methodology presented absolute relative errors 100 times smaller for estimating the benefits of the projects compared to the current method used by the electric power distributor. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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36 pages, 3416 KiB

Open AccessArticle

Beyond Traditional Energy Sector Coupling: Conserving and Efficient Use of Local Resources

by Matthias Maldet, Daniel Schwabeneder, Georg Lettner, Christoph Loschan, Carlo Corinaldesi and Hans Auer

Sustainability 2022, 14(12), 7445; https://doi.org/10.3390/su14127445 - 17 Jun 2022

Cited by 4 | Viewed by 2419

Abstract

Decentralisation and sector coupling are becoming increasingly crucial for the decarbonisation of the energy system. Resources such as waste and water have high energy recovery potential and are required as inputs for various conversion technologies; however, waste and water have not yet been [...] Read more.

Decentralisation and sector coupling are becoming increasingly crucial for the decarbonisation of the energy system. Resources such as waste and water have high energy recovery potential and are required as inputs for various conversion technologies; however, waste and water have not yet been considered in sector coupling approaches but only in separate examinations. In this work, an open-source sector coupling optimisation model considering all of these resources and their utilisation is developed and applied in a test-bed in an Israeli city. Our investigations include an impact assessment of energy recovery and resource utilisation in the transition to a hydrogen economy, with regard to the inclusion of greywater and consideration of emissions. Additionally, sensitivity analyses are performed in order to assess the complexity level of energy recovery. The results demonstrate that waste and water energy recovery can provide high contributions to energy generation. Furthermore, greywater use can be vital to cover the water demands in scarcity periods, thus saving potable water and enabling the use of technology. Regarding the transition to hydrogen technologies, resource energy recovery and management have an even higher effect than in the original setup. However, without appropriate resource management, a reduction in emissions cannot be achieved. Furthermore, the sensitivity analyses indicate the existence of complex relationships between energy recovery technologies and other energy system operations. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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33 pages, 3149 KiB

Open AccessReview

Managing Supply Chain Activities in the Field of Energy Production Focusing on Renewables

by Islam Hassanin and Matjaz Knez

Sustainability 2022, 14(12), 7290; https://doi.org/10.3390/su14127290 - 14 Jun 2022

Cited by 1 | Viewed by 3239

Abstract

Nowadays, the research community focuses on sustainability studies that are at the severe phase in the transformation towards a sustainable world. In addition, reducing the human impact on the environment requires a shift from traditional energy to renewables, which have increased significantly during [...] Read more.

Nowadays, the research community focuses on sustainability studies that are at the severe phase in the transformation towards a sustainable world. In addition, reducing the human impact on the environment requires a shift from traditional energy to renewables, which have increased significantly during recent decades as sustainable energy sources. Hence, this study assesses renewable energy sources and their related production phases from a supply chain management perception, screening and reviewing the integration between the supply chain management within the area of energy production focusing on renewable energy resources. The study executes a systematic review of English literature published on international scientific databases, focusing on the previous decade 2010–2020, to congregate the recently updated knowledge related to such research area. Thus, this study provides an authentic review of the literature that points to the relationship between supply chain operations and the area of renewable energy manufacturing from another side. Several literature reviews have been available concentrating on particular areas of managing renewable energy supply chains; however, no review has highlighted the practices of supply chain processes in energy production, focusing on renewables. The searching process relies on the published works that focus on such an area to be analyzed and characterized based on different methodologies they propose; thus, prospective and future research interests are delineated. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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32 pages, 6129 KiB

Open AccessArticle

Techno-Economic Feasibility of Off-Grid Renewable Energy Electrification Schemes: A Case Study of an Informal Settlement in Namibia

by Aili Amupolo, Sofia Nambundunga, Daniel S. P. Chowdhury and Gunnar Grün

Energies 2022, 15(12), 4235; https://doi.org/10.3390/en15124235 - 9 Jun 2022

Cited by 30 | Viewed by 4665

Abstract

This paper examines different off-grid renewable energy-based electrification schemes for an informal settlement in Windhoek, Namibia. It presents a techno-economic comparison between the deployment of solar home systems to each residence and the supplying power from either a centralized roof-mounted or ground-mounted hybrid [...] Read more.

This paper examines different off-grid renewable energy-based electrification schemes for an informal settlement in Windhoek, Namibia. It presents a techno-economic comparison between the deployment of solar home systems to each residence and the supplying power from either a centralized roof-mounted or ground-mounted hybrid microgrid. The objective is to find a feasible energy system that satisfies technical and user constraints at a minimum levelized cost of energy (LCOE) and net present cost (NPC). Sensitivity analyses are performed on the ground-mounted microgrid to evaluate the impact of varying diesel fuel price, load demand, and solar photovoltaic module cost on system costs. HOMER Pro software is used for system sizing and optimization. The results show that a hybrid system comprising a solar photovoltaic, a diesel generator, and batteries offers the lowest NPC and LCOE for both electrification schemes. The LCOE for the smallest residential load of 1.7 kWh/day and the largest microgrid load of 5.5 MWh/day is USD 0.443/kWh and USD 0.380/kWh, respectively. Respective NPCs are USD 4738 and USD 90.8 million. A sensitivity analysis reveals that variation in the fuel price and load demand changes linearly with system costs and capacities. However, reducing the PV module price in an energy system that includes wind and diesel power sources does not offer significant benefits. Furthermore, deploying an energy system that relies on fossil fuels to each residence in an informal settlement is not environmentally responsible. Unintended negative environmental impacts may result from the mass and simultaneous use of diesel generators. Therefore, a microgrid is recommended for its ability to control the dispatch of diesel generation, and its scalability, reliability of supply, and property security. A roof-mounted microgrid can be considered for piloting due to its lower initial investment. The electricity tariff also needs to be subsidized to make it affordable to end-users. Equally, government and community involvement should be prioritized to achieve long-term economic sustainability of the microgrid. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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10 pages, 996 KiB

Open AccessArticle

Biogas Potential from Slums as a Sustainable and Resilient Route for Renewable Energy Diffusion in Urban Areas and Organic Waste Management in Vulnerable Communities in São Paulo

by Camila Agner D’Aquino, Bruno Alves Pereira, Tulio Ferreira Sawatani, Samantha Coelho de Moura, Alice Tagima, Júlia Carolina Bevervanso Borba Ferrarese, Samantha Christine Santos and Ildo Luis Sauer

Sustainability 2022, 14(12), 7016; https://doi.org/10.3390/su14127016 - 8 Jun 2022

Cited by 8 | Viewed by 2848

Abstract

Slums are populated poor areas inside urban centers, mostly deprived of good-quality public services and exposed to inappropriate waste disposal and energy poverty. Using the organic fraction waste from these communities to generate high value-added products, including electricity, heat, and fertilizer, provides a [...] Read more.

Slums are populated poor areas inside urban centers, mostly deprived of good-quality public services and exposed to inappropriate waste disposal and energy poverty. Using the organic fraction waste from these communities to generate high value-added products, including electricity, heat, and fertilizer, provides a circular bioeconomy with mitigation of greenhouse gas emissions, reducing environmental pollution and diseases. The present study aimed to demonstrate the feasibility of producing bioelectricity from the biogas obtained through the anaerobic digestion of the 400,000 tons of food waste generated in São Paulo’s slums, the largest city in Latin America. The biogas potential was calculated using results obtained from previous studies, expanded to the slums, mapped, and discussed the environmental impact of waste mismanagement and the renewable energy source (RES) integration into the local energy system. The results show a bioelectricity potential of up to 147,734 MWh/y, representing 1.3% of the residential electricity demand with an associated potential reduction of 2111.7 CO₂eq Gg/y. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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16 pages, 2526 KiB

Open AccessArticle

Towards Blockchain-Based Energy Trading: A Smart Contract Implementation of Energy Double Auction and Spinning Reserve Trading

by Uyikumhe Damisa, Nnamdi I. Nwulu and Pierluigi Siano

Energies 2022, 15(11), 4084; https://doi.org/10.3390/en15114084 - 1 Jun 2022

Cited by 19 | Viewed by 4509

Abstract

The decentralization of power generation driven by the rise in the adoption of distributed energy resources paves the way for a new paradigm in grid operations. P2P energy trading is beneficial to the grid as well as the connected peers. A blockchain-based smart [...] Read more.

The decentralization of power generation driven by the rise in the adoption of distributed energy resources paves the way for a new paradigm in grid operations. P2P energy trading is beneficial to the grid as well as the connected peers. A blockchain-based smart contract is well suited to transparently facilitate trades between energy consumers and producers without the services of intermediaries. In this paper, Ethereum-based smart contracts that facilitate double energy auction and spinning reserve trading are developed with Solidity, compiled, and deployed within the Remix IDE. Willing energy sellers/buyers submit offers/bids to a contract that implements the double auction procedure. In order to fulfil energy supply obligations, sellers are also able to purchase spinning reserves via another smart contract. The smart contracts’ effectiveness in performing the auction procedure and making payments is confirmed using an energy/reserve market scenario. The proposed scheme encourages further adoption of distributed energy resources and participation in local P2P energy trading. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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16 pages, 9460 KiB

Open AccessArticle

Assessing the Potential of Implementing a Solar-Based Distributed Energy System for a University Using the Campus Bus Stops

by David Morillón Gálvez, Iván García Kerdan and Germán Carmona-Paredes

Energies 2022, 15(10), 3660; https://doi.org/10.3390/en15103660 - 17 May 2022

Cited by 5 | Viewed by 2178

Abstract

Large educational facilities hold great potential for the implementation of solar-based distributed energy systems. The aim of this paper is to present a prototype and an assessment of a solar-based bus shelter photovoltaic system intended to be implemented at a campus scale that [...] Read more.

Large educational facilities hold great potential for the implementation of solar-based distributed energy systems. The aim of this paper is to present a prototype and an assessment of a solar-based bus shelter photovoltaic system intended to be implemented at a campus scale that serves as an energy-distributed system. The National Autonomous University of Mexico (UNAM), a campus with an area of 7.3 km² and bus stops’ roof area availability of around 1100 m² was selected as a case study. The proposed system, apart from considering on-site generation, also considers an increase in end-use services such as the installation of television screens for information, charging docks, surveillance cameras, internet service, and lighting. For the assessment, a load facility survey and an estimation of the baseline energy use was conducted based on two demand use conditions, corresponding to 12 and 24 h for different archetypical stations. It was found that the baseline annual energy consumption for all the bus stops represents from 55–111 MWh. In this paper, an initial prototype of a solar-based bus shelter PV system is presented, and an assessment is carried out to understand its potential application at a large scale. The analysis shows that energy use in the retrofitted stations would rise to 167 MWh/year; however, apart from covering on-site demand, the system has the capacity to generate an additional 175 MWh, feeding nearby university buildings. It is calculated that the system could save around 130 t CO₂e annually. The economic analysis shows that the project has a discounted payback (DPB) of almost 9 years and an internal rate of return (IRR) of 5.9%; however, in scenarios where renewable generation and carbon incentives are applied, this improves the project’s DPB to 6 years and the IRR to 13%. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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27 pages, 7769 KiB

Open AccessArticle

A Chaotic Search-Based Hybrid Optimization Technique for Automatic Load Frequency Control of a Renewable Energy Integrated Power System

by Nandakumar Sundararaju, Arangarajan Vinayagam, Veerapandiyan Veerasamy and Gunasekaran Subramaniam

Sustainability 2022, 14(9), 5668; https://doi.org/10.3390/su14095668 - 7 May 2022

Cited by 13 | Viewed by 1914

Abstract

In this work, a chaotic search-based hybrid Sperm Swarm Optimized-Gravitational Search Algorithm (CSSO-GSA) is proposed for automatic load frequency control (ALFC) of a hybrid power system (HPS). The HPS model is developed using multiple power sources (thermal, bio-fuel, and renewable energy (RE)) that [...] Read more.

In this work, a chaotic search-based hybrid Sperm Swarm Optimized-Gravitational Search Algorithm (CSSO-GSA) is proposed for automatic load frequency control (ALFC) of a hybrid power system (HPS). The HPS model is developed using multiple power sources (thermal, bio-fuel, and renewable energy (RE)) that generate power to balance the system’s demand. To regulate the frequency of the system, the control parameters of the proportional-integral-derivative (PID) controller for ALFC are obtained by minimizing the integral time absolute error of HPS. The effectiveness of the proposed technique is verified with various combinations of power sources (all sources, thermal with bio-fuel, and thermal with RE) connected into the system. Further, the robustness of the proposed technique is investigated by performing a sensitivity analysis considering load variation and weather intermittency of RE sources in real-time. However, the type of RE source does not have any severe impact on the controller but the uncertainties present in RE power generation required a robust controller. In addition, the effectiveness of the proposed technique is validated with comparative and stability analysis. The results show that the proposed CSSO-GSA strategy outperforms the SSO, GSA, and hybrid SSO-GSA methods in terms of steady-state and transient performance indices. According to the results of frequency control optimization, the main performance indices such as settling time (ST) and integral time absolute error (ITAE) are significantly improved by 60.204% and 40.055% in area 1 and 57.856% and 39.820% in area 2, respectively, with the proposed CSSO-GSA control strategy compared to other existing control methods. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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17 pages, 6063 KiB

Open AccessArticle

Analysis of Pressure Fluctuation of Tubular Turbine under Different Application Heads

by Yaping Zhao, Jianjun Feng, Zhihua Li, Mengfan Dang and Xingqi Luo

Sustainability 2022, 14(9), 5133; https://doi.org/10.3390/su14095133 - 24 Apr 2022

Cited by 7 | Viewed by 1656

Abstract

The vigorous development of low-head hydraulic resources and tidal energy with greater stability and predictability is drawing attention to tubular turbines. However, many problems, such as incorrect unit association relationship, insufficient unit output, and severe vibration, occur frequently in tubular turbines, particularly when [...] Read more.

The vigorous development of low-head hydraulic resources and tidal energy with greater stability and predictability is drawing attention to tubular turbines. However, many problems, such as incorrect unit association relationship, insufficient unit output, and severe vibration, occur frequently in tubular turbines, particularly when the water head is low. These phenomena cannot be known through model machine tests and numerical studies. Therefore, this study takes the tubular turbine with different water heads as the research object, in accordance with the actual boundary conditions. The unsteady numerical research for the prototype machine is conducted while considering the free surface in the reservoir area and water gravity. The internal flow characteristics of the tubular turbine with different water heads and the influence of free surface on its performance are analyzed. The research indicates the following: affected by the free surface and the water gravity, the pressure in the entire flow passage of the horizontal tubular turbine increases with the increase in the submerged depth. In addition, the short water diversion section allows the water flow from the reservoir area to still have a certain asymmetry before reaching the runner. During the rotation process of the runner, the surface pressure and torque of the blade have evident periodic fluctuations, and the amplitude of the fluctuations will increase significantly with the decrease in H/D₁. Moreover, in the case of small H/D₁, the amplitude of pressure pulsation in the draft tube is larger, and concentrated high-frequency pressure pulsation occurs. These factors will lead to the occurrence of material fatigue damage, unstable output, and increased vibration in low-head tubular turbines. Full article

(This article belongs to the Topic Distributed Energy Systems and Resources)

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