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Manufacturers are facing pressure to reduce electricity costs. Onsite renewable energy generation may be a solution, but its high capital cost and intermittent power generation limit its use. Grid-responsive smart manufacturing could effectively incorporate renewables in industrial processes. This study integrates grid-responsive smart manufacturing with renewables on an industrial plant scale and demonstrates both a favourable economic and environmental outcome. A user-friendly decision-aid model for energy management is provided to manufacturers. A case study shows how solar panels, industrial batteries, smart pumping strategies, and various combinations of those elements can save on electricity costs. Dynamic simulation results demonstrate that grid-responsive smart manufacturing can effectively lower peak demand. The economic results show that grid-responsive smart manufacturing and renewables synergistically optimise cost reductions. The solar coupled with smart pumping scenario shows annual cost savings of $755,200, accounting for 4.6% of the total electricity cost. Smart pumping alone saves $371,900 annually with a 0.7-year payback period, demonstrating how the manufacturing sector can utilise its own processes in load shifting. This study supports that incorporating grid-responsive smart manufacturing with renewables can effectively reduce electricity costs and emissions for industry. Abbreviations: e: Equivalent; GHG: Greenhouse gas; PBP: Payback period; PV: Photovoltaics; SP: Setpoint; VFD: Variable speed drives [ABSTRACT FROM AUTHOR]

Given the increasing importance of cascading trip prevention, this study presents the pumped storage characteristics to cooperate with thermal units and further ensure the safety of grid operation. The proposed model comprises two phases: the first phase is the day-ahead decision-making phase, which synergistically optimizes thermal units and pumped storage to improve the flexibility of grid operation; the second phase is the intra-day adjustment phase considering the uncertainty of the wind-photovoltaic and transmission line failure outage to enhance the robustness. Furthermore, this model employs a column and constraint generation algorithm to solve the two-phase, three-layer optimization problem, thereby minimizing the adjustment cost under the riskiest scenarios. The experimental results show that adding pumped storage reduces the total system operating cost by 3.99%, the renewable energy abandonment rate to 0.65%, and the thermal power unit output standard deviation to 74.13 MW. [ABSTRACT FROM AUTHOR]

The role of pumped storage in global energy structure transformation is becoming increasingly prominent. This article introduces a flexible excitation system based on fully controlled device converters into pumped storage units (PSUs). It can address the issues of insufficient excitation capacity and limited stability associated with traditional thyristor excitation systems. The study focuses on linear active disturbance rejection control (LADRC) for the flexible excitation control system of pumped storage units and utilizes intelligent optimization algorithms to optimize the controller parameters. This addresses the inherent problem of traditional PID controllers, which are unable to alleviate the trade-off between response speed and overshoot. At the same time, the robustness and anti-interference of the control system are improved, effectively enhancing the performance of the pumped storage flexible excitation control system. Simulation verifies the feasibility and superiority of the proposed method. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Within the context of carbon peaking and neutrality, carbon capture plants can effectively reduce carbon emissions in power systems. Yet, the regular integration of these units for peak shaving in grids harnessing renewable energy tends to hamper system efficiency. Thus, acknowledging the operation and carbon trading mechanism of adaptable carbon capture plants, firstly, the incorporation of pumped storage plants is suggested to aid peak shaving, thereby facilitating wind power utilization, optimizing carbon capture plants for carbon sequestration, and reducing overall system carbon emissions. Then, given the uncertainty following grid-integrated wind power, fuzzy theory is employed to model system power constraints as fuzzy parameters, representing wind power and load. The constraint is transformed into a credibility-based fuzzy chance constraint. This fuzzy chance constraint is clarified by the clear equivalence classes. Prioritizing maximum system net income as the objective function, elements such as unit online revenue, extraction income, carbon trading profits, operational costs, and system security constraints are considered. The carbon capture-pumped storage joint operation model is developed. Finally, the model is solved using CPLEX. Simulation results validate that the integration of pumped storage plant enhances the system′s net income by 7.62% and reduces carbon emissions by 7.01%, reflecting a balanced consideration of both economic and environmental aspects.

For recent hydroelectric pumped storage projects, the construction of embankment dam structures on alluvial deposits consisting of exceptionally soft soil and in areas with high seismicity was required. This contribution shares experiences and challenges from the static and seismic design of embankment dam structures and ground treatment options. Finite element‐based static and seismic analyses using the Hardening Soil Small Strain model (HSS) showed that preconsolidation has clear benefits compared to stone columns for ground improvement purposes. Regardless of general advantages of surface sealing systems for frequent and rapid impoundment level changes, it was found that clay core design options perform very well under seismic loading conditions and even better than surface‐sealed structures. Seismic ground and structure response analyses involving soft soil considering shear strain‐dependent stiffness degradation revealed that deamplification is expected in contrast to the rule‐of‐thumb amplification approaches enshrined in many seismic design guidelines and codes. It was found that this effect increases with seismic magnitudes and that saturation of peak ground acceleration (PGA) takes place. This results in relatively moderate structure excitations even under significant dynamic excitation. [ABSTRACT FROM AUTHOR]

Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the "net-zero carbon" target, a higher proportion of variable renewable energies (VREs) has been integrated into power grids, and pumped storage plants (PSPs) are crucial for guaranteeing the safe and stable operation of hybrid energy systems. As secondary frequency regulation (SFR) is related to the economic operation and the quality of auxiliary services provided by PSPs, it is critical to clarify its performance and compensation. Therefore, the corresponding quantitative evaluations of the SFR of pumped storage units (PSUs) are carried out in this paper. First, the performance of SFR is quantified based on the fuzzy analytic hierarchy process (FAHP). Considering the current situation in China's electricity market, the average compensation of the PSP with each MW is determined to be 9.336 CNY per day, and a method for calculating the compensation of SFR is constructed. Then, taking a real Chinese PSP as an example, based on different wind power deviation signals, the quantitative evaluation of the compensation of SFR is conducted in accordance with the fixed-speed pumped storage units (FSPSUs) and the variable-speed pumped storage units (VSPSUs) in power priority and speed priority modes. The results show that the compensation of FSPSUs and VSPSUs (power priority mode and speed priority mode) is 10,900 CNY per day; 54,400 CNY per day; and 17,300 CNY per day. This paper could contribute to clarifying the compensation of SFR and providing technical support for the development of the auxiliary service market. [ABSTRACT FROM AUTHOR]

Low carbon operation of power systems is a key way to achieve the goal of energy power carbon peaking and carbon neutrality. In order to promote the low carbon transition of energy and power and the coordinated and optimized operation of distributed energy sources in virtual power plants (VPP), this paper proposes a framework for collaborative utilization of pumped storage–carbon capture–power-to-gas (P2G) technologies. It also constructs a multi-time scale low carbon economic dispatch model for VPP to minimize the internal resource operation cost of VPP in each time period. During the intraday scheduling stage, the day-ahead scheduling results as the planned output and the energy flow is then dynamically corrected at a short-term resolution in the framework. This allows for the exploration of the low-carbon potential of each aggregation unit within the virtual power plant. The results of the simulation indicate that the strategy and model proposed in this paper can effectively encourage the consumption of renewable energy sources, promote the low-carbon operation of power system power, and serve as a valuable reference for the low-carbon economic operation of the power system. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power Engineering Technology is the property of Editorial Department of Electric Power Engineering Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Innovative approaches to the development of clean energy are seen as a significant driving force for achieving China’s “dual carbon” goals. To address the challenge of unstable electricity supply from large-scale renewable energy, the construction and development of pumped storage power plants have been promoted through the proposal and rapid growth of new power systems. However, some traditional pumped storage power plants have been constrained by factors such as ecological protection and terrain. On the other hand, a unique solution is provided by repurposing or closing abandoned mines. Due to their abundant water and space resources, closed/abandoned mines can be innovatively developed for pumped storage energy, thereby extending the economic lifespan of mining areas and reducing negative impacts on the environment and economy. The technological advancements and application progress of abandoned mine pumped storage energy technology, both domestically and internationally, are comprehensively reviewed in this study through literature analysis, aiming to establish suitable utilization models and management systems for abandoned mine pumped storage energy in line with China’s national conditions. Detailed explanations of the principles, classifications, advantages, and disadvantages of closed/abandoned mine pumped storage energy technology are provided. The utilization models of closed/abandoned mine pumped storage power stations are summarized, and the site selection factors are revised based on previous research. Additionally, the current research status of two-phase flow characteristics in pumped storage power stations, water pump-turbine operating conditions, stability of surrounding rock in underground spaces, and calculation of underground water storage space volume are reviewed. Key technical challenges that urgently need to be addressed, such as pump-turbine technology and control of underground space stability, are identified. Furthermore, an extensive literature review is conducted on the ecological and environmental protection, market demand and economic benefits, and policies and regulations related to closed/abandoned mine pumped storage. The development of closed/abandoned mine underground space pumped storage technology can provide some insights into the utilization of underground space resources in China and offer new pathways for ensuring national energy security and high-quality socio-economic development.

To address the flexible and economical peak shaving issue of power grid in the presence of large-scale renewable energy penetration, a multi-source complementary peak shaving scheduling method with detailed consideration of nuclear power risk quantification is proposed. Firstly, the mechanism of low load peak shaving for nuclear power is analyzed, and its peak shaving risk quantitative indicators are considered to balance its economical efficiency and safety. Secondly, a wind-solar-thermal-nuclear-storage based multi source complementary peak shaving scheduling model is established, which takes the minimum total operating cost as the optimization goal, and considers the loss of wind and solar power waste and the increased power generation cost of different power sources participating in peak shaving, and the mode is solved. Finally, case study demonstrates the effectiveness of the proposed optimization scheduling model and its superiority. The results show the proposed method can achieve a 94.17% reduction in wind and solar waste compared to thermal power peak shaving and nuclear power peak shaving without energy storage participation, and a 1.26% reduction in carbon emissions. This indicates a significant improvement of the peak shaving ability of a high proportion of wind and solar power grid within multi source complementary mode. The proposed method provides a practical approach to realize economical and low carbon economy operation of multi source complementary system.

In the context of energy conservation and emission reduction, the integration and consumption of large-scale wind and solar resources is an inevitable trend in future energy development. However, with the increase of wind and solar grid-connected capacity, the power system also requires more flexible resources to ensure safe operation. To enhance the economic efficiency of the complementary operation of wind, solar, hydro, and thermal sources, considering the peak regulation characteristics of different types of power sources, the study of the joint dispatch model of complementary utilization of various generation methods like wind, solar, hydro, thermal, and storage is of great significance for the economic dispatch of the power system. Existing studies mainly focus on traditional thermal power units or hydropower units, with few studies investigating the impact of pumped-storage power stations on the absorption of renewable energy. Firstly, this paper introduces the composition and function of each unit under the research framework and establishes a joint dispatch model for wind, solar, hydro, and thermal power. Secondly, the paper elaborates on the objective function within the model, mainly covering the operating costs of thermal power units, hydropower units, pumped storage, wind and solar units, the cost of discarding new energy, and the cost of load shedding. Subsequently, the paper presents the constraints of the system model, mainly the feasible boundaries for the operation of each unit within the system. Finally, The results of the calculations show that the proposed model reduces the total operating cost by 12% and the power abandonment rate by 82% compared to the conventional model. It is shown that the proposed model can not only significantly improve the economic efficiency of the system operation but also reduce the level of energy waste and load shedding, effectively enhancing the degree of energy utilization within the system. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power Engineering Technology is the property of Editorial Department of Electric Power Engineering Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to help achieve the goal of "Double Carbon" and the recycling of waste and renewable resources, the use of the mined-out areas left behind by mining to build clean energy power stations in Yunnan Province is in line with the practical needs of the country. In the actual process of transforming abandoned mines, the realization of multiple development and utilization modes is more conducive to the penetration of renewable energy and the maintenance of the stable operation of the power grid. According to the principle of water-optical complementary power generation, combined with the characteristics of natural resources and energy endowment in Yunnan Province, this paper discusses the feasibility of constructing abandoned mine photovoltaic-pumped storage power plant in Yunnan province from the working principle and structure of abandoned mine photovoltaic-pumped storage power plant, key technologies, and the estimation of economic benefits, and other aspects. The analysis results in show that Yunnan Province has accumulated more than 1. 5 billion m³ of mining area and rich natural resources, energy for the construction of photovoltaic-pumped storage power plants provides favourable conditions; and the proportion of clean electricity in Yunnan Province in recent years has also rising, and in 2022, the proportion of clean electricity has reached 87. 7% ;by the example of the abandoned mine photovoltaic-pumped storage power plant calculations, the mine can be generated annually by the amount of electricity Revenue amounted to 120 million yuan, according to the design life of 20 years, the total output of about 2. 4 billion yuan of revenue. In summary, the advantages of constructing a PV-pumped storage power plant for abandoned mines in Yunnan Province are significant. [ABSTRACT FROM AUTHOR]

The role of pumped storage in global energy structure transformation is becoming increasingly prominent. This article introduces a flexible excitation system based on fully controlled device converters into pumped storage units (PSUs). It can address the issues of insufficient excitation capacity and limited stability associated with traditional thyristor excitation systems. The study focuses on linear active disturbance rejection control (LADRC) for the flexible excitation control system of pumped storage units and utilizes intelligent optimization algorithms to optimize the controller parameters. This addresses the inherent problem of traditional PID controllers, which are unable to alleviate the trade-off between response speed and overshoot. At the same time, the robustness and anti-interference of the control system are improved, effectively enhancing the performance of the pumped storage flexible excitation control system. Simulation verifies the feasibility and superiority of the proposed method.

With the development of the electricity spot market, pumped-storage power stations are faced with the problem of realizing flexible adjustment capabilities and limited profit margins under the current two-part electricity price system. At the same time, the penetration rate of new energy has increased. Its uncertainty has brought great pressure to the operation of the power system. The ramp market and its market mechanism have emerged as the times require. To this end, this article proposes a bidding strategy for pumped-storage power stations to participate in multi-level markets such as the ramp market. Considering the demand calculation of ramping services, a two-layer model of pumped storage's participation in multiple markets is constructed. The upper level makes trading decisions with the goal of maximizing pumped-storage revenue; the lower level aims to minimize the total social cost and jointly clears the primary and auxiliary markets. The income from pumped storage participating in the main energy and ramp-up auxiliary markets at the same time is significantly higher than the income from the two-part electricity price system. Its flexible adjustment ability can be quantified, reducing dependence on capacity electricity charges and providing a theoretical reference for cost recovery and profitability of future pumped-storage power stations. [ABSTRACT FROM AUTHOR]

Aiming to mitigate the impact of power fluctuation caused by large-scale renewable energy integration, coupled with a high rate of wind and solar power abandonment, the multi-objective optimal dispatching of a cascade hydro–wind–solar–thermal hybrid generation system with pumped storage hydropower (PSH) is proposed in this paper. Based on the proposed system, the scheduling operation strategy takes into account the complex restrictions of cascade hydropower as well as the flexibility of the PSH. According to various scenarios, the NSGA-II approach is adopted to address the optimization problem, minimizing the system's residual load variation and operation cost. The Pareto solution sets are contrasted and evaluated, applying the TOPSIS with CRITIC weighting. Additionally, the scheduling output of thermal power, cascade hydropower, and PSH is given in terms of different scenarios. The results demonstrate that the allocation of PSH to a hybrid energy system can significantly reduce the operation cost and the fluctuation in the residual load. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power is the property of Electric Power Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As flexible resources, cascaded hydropower stations can regulate the fluctuations caused by wind and photovoltaic power. Constructing pumped-storage units between two upstream and downstream reservoirs is an effective method to further expand the capacity of flexible resources. This method transforms cascaded hydropower stations into a cascaded pumped-hydro-energy storage system. In this paper, a flexibility reformation planning model of cascaded hydropower stations retrofitted with pumped-storage units under a hybrid system composed of thermal, wind, and photovoltaic power is established with the aim of investigating the optimal capacity of pumped-storage units. First, a generative adversarial network and a density peak clustering algorithm are utilized to generate typical scenarios to deal with the seasonal fluctuation of renewable energy generation, natural water inflow, and loads. Then, a full-scenario optimization method is proposed to optimize the operation costs of multiple scenarios considering the variable-speed operation characteristics of pumped storage and to obtain a scheme with better comprehensive economy. Meanwhile, the proposed model is retransformed into a mixed-integer linear programming problem to simplify the solution. Case studies in Sichuan province are used to demonstrate the effectiveness of the proposed model. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the context of energy conservation and emission reduction, the integration and consumption of large-scale wind and solar resources is an inevitable trend in future energy development. However, with the increase of wind and solar grid-connected capacity, the power system also requires more flexible resources to ensure safe operation. To enhance the economic efficiency of the complementary operation of wind, solar, hydro, and thermal sources, considering the peak regulation characteristics of different types of power sources, the study of the joint dispatch model of complementary utilization of various generation methods like wind, solar, hydro, thermal, and storage is of great significance for the economic dispatch of the power system. Existing studies mainly focus on traditional thermal power units or hydropower units, with few studies investigating the impact of pumped-storage power stations on the absorption of renewable energy. Firstly, this paper introduces the composition and function of each unit under the research framework and establishes a joint dispatch model for wind, solar, hydro, and thermal power. Secondly, the paper elaborates on the objective function within the model, mainly covering the operating costs of thermal power units, hydropower units, pumped storage, wind and solar units, the cost of discarding new energy, and the cost of load shedding. Subsequently, the paper presents the constraints of the system model, mainly the feasible boundaries for the operation of each unit within the system. Finally, The results of the calculations show that the proposed model reduces the total operating cost by 12% and the power abandonment rate by 82% compared to the conventional model. It is shown that the proposed model can not only significantly improve the economic efficiency of the system operation but also reduce the level of energy waste and load shedding, effectively enhancing the degree of energy utilization within the system.

With the breakthrough of key technologies of renewable energy, microgrid is gradually developing towards 100% renewable energy. However, aiming at the characteristics of renewable energy power such as randomness and intermittency, the microgrid needs to cope with the “double” fluctuations from the power source side and the load side, which will pay more costs for absorbing renewable energy. To implement “source-grid-load-storage” integration, this research establishes a hierarchical scheduling model for microgrid, which considers the demand response (DR) characteristics of electric vehicle (EV) users and is 100% powered by renewable energy. The model includes two layers, EV layer and renewable energy microgrid (REMG) layer. The first layer is EV layer. This layer formulates an appropriate charging price according to the user’s price response characteristics, and initially regulates the fluctuation of the original load while taking into account the customer satisfaction. The second layer is REMG layer. Based on the preliminarily optimized load, this layer adjusts the renewable energy rejection, the interactive power of main grid, and the output of pumped storage and battery storage under grid connection mode and island mode. The REMG layer can reduce system operating costs, while suppressing interactive power fluctuations and increasing the utilization rate of renewable energy. Simulation shows that the proposed optimal scheduling model can achieve win-win between EV and users.

Low carbon operation of power systems is a key way to achieve the goal of energy power carbon peaking and carbon neutrality. In order to promote the low carbon transition of energy and power and the coordinated and optimized operation of distributed energy sources in virtual power plants (VPP), this paper proposes a framework for collaborative utilization of pumped storage–carbon capture–power-to-gas (P2G) technologies. It also constructs a multi-time scale low carbon economic dispatch model for VPP to minimize the internal resource operation cost of VPP in each time period. During the intraday scheduling stage, the day-ahead scheduling results as the planned output and the energy flow is then dynamically corrected at a short-term resolution in the framework. This allows for the exploration of the low-carbon potential of each aggregation unit within the virtual power plant. The results of the simulation indicate that the strategy and model proposed in this paper can effectively encourage the consumption of renewable energy sources, promote the low-carbon operation of power system power, and serve as a valuable reference for the low-carbon economic operation of the power system.

Abstract The ultra‐low frequency oscillation and poor speed regulation performance caused by the fast power control decrease the stability and efficiency of the variable speed pumped storage unit with a full size converter (FSC‐VSPSU). This paper presents a fast frequency control strategy to solve this problem. The small‐signal model of the FSC‐VSPSU in fast frequency mode is established, and the key parameters for the system stability are studied by the eigenvalue method. Aiming at the coupling oscillation mode caused by the governor and generator side converter (GSC), the corresponding control parameters optimisation method is proposed. In order to solve the power anti‐regulation problem, the strategy of combining rotor kinetic energy release, power slope adjustment, and delay acceleration control is proposed. PSCAD and RTDS simulation results show that the proposed strategy can effectively avoid the ultra‐low frequency oscillation caused by the fast power control and significantly improves the frequency and power control performance.

To achieve carbon peaking and carbon neutrality, China has deepened its energy revolution with the largest renewable energy power generation capacity in the world.In face of the unstable power supply of large-scale renewable energy, a new power system has been proposed and constantly upgraded, which promoted the construction and development of pumped storage power station.Under terrain constraints and the ecological red line, the site selection of traditional pumped storage power station is a hard nut to crack.At the same time, a large number of closed/abandoned mines and resource exhausted cities emerged in the process of coal capacity reduction.This study gave a detailed overview of the status quo of pumped storage power station in China, and analyzed the environmental benefits of the combination of closed/abandoned mines and pumped storage, such as water resource pressure relief and greenhouse gas emission reduction.Based on the different modes of closed/abandoned mine pumped storage power stations, this study analyzed the application potential of closed/abandoned mine pumped storage.Finally, this paper proposed the development strategy of China's abandoned mine pumped storage, and the prospects of closed/abandoned mine+energy storage in multiple industries.

Copyright of EMERG: Energy. Environment. Efficiency. Resources. Globalization is the property of Romanian National Committee of World Energy Council and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pumped storage technology is recognized as an important technology for achieving “peak carbon and carbon neutrality”. In order to understand the core of pumped storage technology and objectively discuss the current research status and hot issues of this technology, the patents of pumped storage technology in the Derwent patent database of Web of Science were analyzed metrologically. The paper constructed a knowledge map and combined it with complex network analysis. The important factors can be considered by the development of pumped storage technology and the spatial and temporal distribution of patents, the overall frontier and hot technologies, the collaboration between patent rights and the significant factors to be considered when building pumped storage plants. The results are as follows. Firstly, most of the technology patents in the field of pumped storage come from China. The current cutting-edge research is focused on technologies such as hybrid solar and pumped storage power generation systems, balancing network loads and how to reduce or prevent power oscillations. Secondly, the inter-institutional cooperation network is a scale-free network in which State Grid Corporation plays a very important intermediary role. Finally, the construction of pumped storage power plants should be carried out with a specific analysis of the terrain and the abundance of local clean energy. It is also necessary to focus on the upgrading of relevant equipment technologies and the updating of operation and management technologies. [ABSTRACT FROM AUTHOR]

The development of high-head pumped-storage projects presents various opportunities and challenges. One challenge is the operational stability of pumped-storage power plants, which is closely associated with the characteristics of pump-turbines. In this study, the design and experimental verification of the hydraulic performance of a pump-turbine runner with splitter blades are investigated. The effects of several main parameters on the performance curve and S-shaped characteristics of pump-turbines in turbine mode are examined via numerical simulation. Subsequently, model tests are conducted to validate the improvements in the performance curve, including a comparison of the S-shaped characteristic curve at a constant guide vane opening and under the same initial conditions. An emergency load rejection test based on the same guide vane closing scheme is performed to verify improvements in transient pressure in the spiral case, draft tube, and rotational speed. The results confirm the enhancement in the S-shaped characteristics and transient global parameters of the splitter blade design. Furthermore, a reduction in pressure pulsation intensity in the vaneless space during off-design conditions is confirmed. [ABSTRACT FROM AUTHOR]

The ultra‐low frequency oscillation and poor speed regulation performance caused by the fast power control decrease the stability and efficiency of the variable speed pumped storage unit with a full size converter (FSC‐VSPSU). This paper presents a fast frequency control strategy to solve this problem. The small‐signal model of the FSC‐VSPSU in fast frequency mode is established, and the key parameters for the system stability are studied by the eigenvalue method. Aiming at the coupling oscillation mode caused by the governor and generator side converter (GSC), the corresponding control parameters optimisation method is proposed. In order to solve the power anti‐regulation problem, the strategy of combining rotor kinetic energy release, power slope adjustment, and delay acceleration control is proposed. PSCAD and RTDS simulation results show that the proposed strategy can effectively avoid the ultra‐low frequency oscillation caused by the fast power control and significantly improves the frequency and power control performance. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power is the property of Electric Power Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Incorporating renewable energy storage systems in power grids has presented significant challenges in maintaining a stable power generation structure and load frequency within interconnected grids. A promising solution to support the reliable and safe operation of the power system is the use of pumped storage units because of their excellent adjustment characteristics, including fast power response and convenient start and stop features. To optimize the performance of the pumped storage system, this article proposes the implementation of a linearadaptive disturbance rejection controller (LADRC) in conjunction with the segmentation particle swarm optimization (Se-PSO) algorithm for parameter tuning. This article establishes a precise hybrid load frequency control (LFC) model for a two-area interconnected power grid incorporating pumped storage power plants (PSPP). It determines the optimal LADRC parameters for varying load disturbances in different areas of the power grid. The proposed control method systematically simulated pumping and power generation conditions in a PSPP. Simulation results indicate that the proposed method enhances dynamic stability by approximately 85%, offering greater antidisturbance ability and adaptability than the traditional proportional-integral (PI) controller. [ABSTRACT FROM AUTHOR]

With the increasing global demand for sustainable energy sources and the intermittent nature of renewable energy generation, effective energy storage systems have become essential for grid stability and reliability. This paper presents a comprehensive review of pumped hydro storage (PHS) systems, a proven and mature technology that has garnered significant interest in recent years. The study covers the fundamental principles, design considerations, and various configurations of PHS systems, including open-loop, closed-loop, and hybrid designs. Furthermore, the review highlights the crucial role of PHS systems in integrating renewable energy sources, mitigating peak load demands, and enhancing grid stability. An in-depth analysis of current and emerging trends, technical challenges, environmental impacts, and cost-effectiveness is also provided to identify potential areas for future research and development. The paper concludes by offering a perspective on the challenges and opportunities that PHS systems present, underlining their potential to significantly contribute to a sustainable and reliable energy future. [ABSTRACT FROM AUTHOR]

To cooperate with new energy sources such as wind and solar, pumped storage units are required to frequently change conditions and operate under part loads, leading to the problem of violent pressure fluctuation and unit vibration. To meet this challenge, the next generation of pump-turbine runners will therefore have to be designed differently. The goal of this article is to construct a framework for broadening the operating range of pump-turbine to deep-part loads. In this study, a multi-objective optimization strategy for the runner with wider output range is suggested, wherein the blade control parameters, specifically the blade loading and blade lean angle, are optimized to enhance the efficiency, anti-cavitation, and stability of the pump-turbine runner. A runner with turbine output range of 40%–100% is optimized for a specific power station. Next, the impact of runner control parameters on runner performance is evaluated, and the runner geometric characteristics for different optimizing priorities such as the pump peak efficiency, cavitation performance, turbine rated efficiency, and turbine partial load efficiency, are concluded. The mutual restriction mechanism between the pump peak efficiency and cavitation performance of pump mode, as well as the turbine-rated efficiency and partial load efficiency of turbine mode, is revealed. The main contributions of this paper include putting forward an effective optimization design process for wide output pump-turbine, and pointing out the relationship between runner geometric characteristics and performance. The results indicate that the present approach can significantly improve the efficiency and stability of runners operating in deep-part loads. The blade loading pattern with hub section aft-loaded and shroud section fore-loaded, combined with negative blade lean angle, is recommended for such runners. Blades with a smaller wrap angle and lower arch are conducive to improving the pump peak efficiency and turbine-rated efficiency, while the opposite geometrical features are advantageous for improving the runner cavitation performance and efficiency performance under part load conditions. These findings can serve as an important guide for the development of runners with a wider output range. [ABSTRACT FROM AUTHOR]

Recently, renewable energy resources (RESs) have been utilized to supply electricity to remote areas, instead of the conventional methods of electrical energy production. In this paper, the optimal design of a standalone hybrid RES comprising photovoltaic (PV), wind turbine (WT), and biomass sources as well as an energy storage system, such as a hydro-pumped storage system, is studied. The problem of the optimal sizing of the generating units in the proposed energy system is formulated as an optimization problem and the algorithms heap-based optimizer (HBO), grey wolf optimizer (GWO), and particle swarm optimization (PSO) are applied to achieve the optimal sizing of each component of the proposed grid-independent hybrid system. The optimization problem is formulated depending on the real-time meteorological data of the Ataka region on the Red Sea in Egypt. The main goal of the optimization process is to minimize the cost of energy (COE) and the loss of power supply probability (LPSP), while satisfying the constraints of system operation. The results clarify that the HBO algorithm succeeded in obtaining the best design for the selected RE system with the minimum COE of 0.2750 USD/kWh and a net present cost (NPC) of USD 8,055,051. So, the HBO algorithm has the most promising performance over the GWO algorithm in addressing this optimization problem. [ABSTRACT FROM AUTHOR]

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Copyright of Electric Power is the property of Electric Power Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Large Electric Machine & Hydraulic Turbine is the property of Large Electric Machine & Hydraulic Turbine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Seeking 100% renewable energy source (RES) penetration in low-inertia, isolated grids presents major challenges, including frequency control and stability. This is the case in small island systems relying on variable RES and pumped-hydro storage, where the limited ramping capabilities of hydro turbines compromise their frequency response. In this study, solutions are examined to allow the operation of such systems under 100% RES conditions. The Greek island of Ikaria is used as a study case, supplied by a hybrid RES-storage facility, consisting of hydroelectric units, a pumping facility and a wind farm. Solutions under study include the implementation of deflector control to allow provision of fast reserves by the Pelton hydro turbines, primary reserves provision by the wind farm, the enhancement of the variable speed pump control to contribute to primary frequency regulation, and, at a further step, the installation of battery energy storage to provide fast response for effective frequency regulation. All solutions are comparatively assessed via simulation to demonstrate that the proposed deflector control allows effective frequency regulation, albeit at the detriment of energy efficiency, whereas the variable speed pumps may also contribute to primary regulation in case of contingencies. It is battery storage that would decisively enhance frequency control and security of operation, while also allowing for improved tracking of wind power variations in normal operation; best results are achieved when batteries are combined with the other supplementary regulation measures, allowing a reduced battery capacity.

In order to overcome the randomness and intermittency of wind power generation and maximize the use of wind energy, a power generation system combined with wind power generation and pumped storage is constructed. Aiming at its operation optimization problem, this paper comprehensively considers the utilization of wind energy, the impact on power grid and overall economic benefits, takes the maximization of wind power utilization, the minimization of grid connected power fluctuations and the maximization of the economic benefits of combined power generation as the optimization objectives, considers the constraints such as power balance of generator units and power grid, and establishes a three-objective optimization model of the wind power & pumped storage combined power generation system. In order to solve the model, based on the basic whale optimization algorithm, a multi-objective whale optimization algorithm is developed by adding external population and leader selection mechanism, and the control parameter in the algorithm is improved to obtain an improved multi-objective whale optimization algorithm. Simulation results show that the convergence, distribution and uniformity of the improved multi-objective whale optimization algorithm are better than the multi-objective particle swarm optimization algorithm and the basic multi-objective whale optimization algorithm, which verifies the effectiveness and superiority of the proposed improved multi-objective optimization method. Select the appropriate solution from the obtained optimal solution set to obtain the operation optimization strategy of the combined power generation system, which can achieve better economic benefits and maximum wind energy utilization while smoothing the system output power.

Abstract A seawater reverse osmosis (RO) plant layout based on multistage RO with stages located at different elevations above sea level is described. The plant uses the weight of a seawater column from pumped storage as head pressure for RO (gravity-driven multistage RO) or to supplement high-pressure pumps used in RO (gravity-assisted multistage RO). The use of gravitational force reduces the specific energy for RO compared to using high-pressure pumps. By locating the RO stages at different elevations based on demand sites, the total specific energy consumption for RO and permeate transport to different elevations above sea level is reduced from that for locating the RO process entirely at sea level followed by lifting the desalinated water. A final RO stage at sea level uses seawater pressurized by energy recovery from the residual energy of the brine generated from the preceding RO stage. Examples of the plant layout that do not include pump inefficiency and head losses in pipes are described for South Sinai, Egypt, which is a mountainous region that suffers from water scarcity. A gravity-driven multistage RO with a storage tank at 660 m above sea level is considered. For five RO stages located 316–57 m above sea level with 10% recovery at each stage, the specific energy is ~ 32% lower than that for a plant located at sea level operating at the minimum specific energy followed by lifting the same quantity of desalinated water to the elevations of the distributed RO stages. For two stages located at 222 and 57 m above sea level with 30 and 20% recovery, respectively, the reduction in specific energy is ~ 27%. For gravity-assisted five-stage RO with the first stage at 260 m above sea level, while the last stage is at sea level with 10% recovery at each stage the reduction in specific energy is ~ 32%. The proposed RO plant layouts can be adapted to other regions with comparable topography.

With the development of the electricity market in China, regulations are updated quickly and models adapted to the latest policies need to be developed urgently. This paper proposes a combined clearing model to make pumped storage units participate the spot market. Three income models of the grid companies are developed as well. A 39-bus test system is introduced for simulation and the results show that pumped storage could increase its revenue and bring cost reduction for the system when participating the spot market. The income of the grid company would experience a 35% increase after adopting the possible future policy.

Multi-energy complementarity is an important means to solve the problem of renewable energy consumption. In this paper, the economic evaluation model of Wind–Photovoltaic (PV)–Pumped Storage (PS) hybrid system with different scenarios of installed capacity is constructed based on the high proportion of wind and PV accessing to power grids. Firstly, an index system covering techno-economic, financial and social and environmental benefits is established under the guidance of the SMART Principle. The influence of carbon emissions is considered in the index for social and environmental benefits. Then the combination weighting method is used to weigh each index, afterwards the total score is calculated by the nonlinear weighted method. Finally, the model is applied to solve and analyze the hybrid system under 22 scenarios. The result shows the nonlinear correlation between comprehensive economic benefits and the installed capacity, and presents the local maximum of the economic benefits in a certain range as well.

The tailwater tunnel of the Wuyue pumped storage power station is located in bedrock and extends to depths between tens and hundreds of meters. It is impossible to analyze and evaluate the whole engineering area from geological exploration data, and the hydrogeological conditions are complicated. In the early stages of the tailwater tunnel's construction, the drinking water wells in four villages dried up. This paper reports the results from a field investigation, in situ tests, laboratory tests, and numerical simulation carried out to determine how the groundwater was affected when the tunnel was excavated. A hydrogeological model of the region was established from the inverted regional natural flow field parameters. The model was validated, and an analysis of the errors showed that there was an average error of 1.98% between the natural flow field and the hydrogeological survey flow field. The model was then used to simulate the three-dimensional transient seepage fields under normal seepage conditions and limited seepage conditions, as far as was practical. The results showed that, as the excavation of the tailwater tunnel advanced, the water inflow to the tunnel also increased. When the water inflow increased from 1000 to 5000 m3/d, the water level at a distance of 100 m from the axis of the tunnel dropped from −0.956 to −1.604 m. We then analyzed how the water level changed as the water inflow varied and proposed a formula for calculating the extent of the influence on the groundwater. We studied how the water level changed at different well points to ascertain how a groundwater well became depleted and determined the factors that influenced seepage in the regional flow field. The water level in different areas of the project area was simulated and analyzed, and the extent of the groundwater area affected by the tunnel construction was clarified. We then studied how the groundwater in different areas of, and distances from, the project area was influenced by normal seepage conditions and limited seepage conditions and proposed a formula for calculating the extent of the influence on groundwater for different water inflows. We constructed a 'smart site' for visualizing data, sharing information, and managing the project. Time–frequency domain analysis was applied to explore the extent of the impacts and range of the vibration effects on residential housing at different distances from the project area caused by the different methods for excavating the tailwater tunnel. The results from this analysis will provide useful insights into how the excavation of this tailwater tunnel will impact the local residents and living areas. [ABSTRACT FROM AUTHOR]

With the increase in the designed net head and output capacity, the operational stability of the pump turbine, which is the core component of a pumped storage power station, requires further investigation. The originality of the current research lies in the analysis of the pressure pulsation characteristics in the vaneless space of a pump-turbine runner designed with splitter blades. Under the designed net head and high-flow-rate conditions, the dominant frequency of the pressure pulsation in the vaneless space corresponds to half the total number of runner blades, 4 f n. As the flow rate decreases, a blade-passing frequency of 8 f n corresponding to the total number of runner blades was observed. Subsequently, the amplitude of 8 f n increased, which gradually became the dominant frequency, whereas that of 4 f n diminished. The contribution of current research is that the transition of the amplitude-frequency characteristic of the rotor-stator interaction of pump-turbine runners with splitter blades is revealed, which is significantly different from the analysis of equal-blade pump-turbines in the existing literature. For pumped storage power stations equipped with pump-turbine runners with splitter blades, it is necessary to consider the dominant frequency in the vaneless space to avoid the adverse effect of the transition of the dominant frequency of the rotor–stator interaction on the structural response of the station. [ABSTRACT FROM AUTHOR]