Pumped Storage Research Articles

Influence of asymmetric-paths winding on electromagnetic force of variable speed pump storage generator-motor

Stator asymmetric-paths winding of variable speed pump storage (VSPS) generator-motor can solve the problem of mismatch of unit speed, capacity and outlet voltage. However, different winding connection schemes will lead to the change of magnetomotive force (MMF) asymmetry of each branch, and then affect the electromagnetic force of generator-motor. In order to explore the effect of this winding type on the electromagnetic force, stator asymmetric-paths winding's MMF and electromagnetic force of 336 MW VSPS generator-motor is derived. Waveforms and harmonic contents of the stator asymmetric-paths winding MMF of the equal-pitch and unequal-pitch schemes are analyzed. Under the consideration constraints of factors such as minimizing MMF asymmetry and electromagnetic vibration, a reasonable asymmetric-paths winding scheme with unequal pitch is determined It is concluded that asymmetric-paths winding scheme with pitch of 14-15-16 can effectively weaken the low-order MMF harmonics and reduce the electromagnetic force under the limitation of asymmetric-paths winding form. The finite element model of VSPS generator-motor is further developed, and the electromagnetic force amplitude and spatial and temporal distribution characteristics under 6 winding schemes are calculated to verify the accuracy of the calculation model. The results of the study can provide technical support for the development of localized VSPS generator-motor.

Assessing the Flexibility Potential of Industrial Heat–Electricity Sector Coupling through High-Temperature Heat Pumps: The Case Study of Belgium

Thermal processes represent a significant fraction of industrial energy consumptions, and they rely mainly on fossil fuels. Thanks to technological innovation, highly efficient devices such as high-temperature heat pumps are becoming a promising solution for the electrification of industrial heat. These technologies allow for recovering waste heat sources and upgrading them at temperatures up to 200 °C. Moreover, the coupling of these devices with thermal storage units can unlock the flexibility potential deriving from the industrial sector electrification by means of Demand-Side Management strategies. The aim of this paper is to quantify the impact on the energy system due to the integration of industrial high-temperature heat pumps and thermal storage units by means of a detailed demand–supply model. To do that, the industrial heat demand is investigated through a set of thermal process archetypes. High-temperature heat pumps and thermal storage units for industrial use are included in the open-source unit commitment and optimal dispatch model Dispa-SET used for the representation of the energy system. The case study analyzed is Belgium, and the analysis is performed for different renewable penetration scenarios in 2040 and 2050. The results demonstrate the importance of a proper sizing of the heat pump and thermal storage capacity. Furthermore, it is obtained that the electrification of the thermal demand of industrial processes improves the environmental impact (84% reduction in CO2 emissions), but the positive effect of the energy flexibility provided by the heat pumps is appreciated only in the presence of a very high penetration of renewable energy sources.

Capacity Allocation Method of Pumped-Storage Power Station for Multi-Level Market in New Power System

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.

CFD Investigation of the Hydraulic Short-Circuit Mode in the FMHL/FMHL+ Pumped Storage Power Plant

The flexibility of the FMHL+ pumped storage power plants can be improved by extending the hydraulic short-circuit operating mode. CFD simulations of the flow in three bifurcations are performed to calculate the head losses and to investigate the flow topology in the pipes. A specific attention is paid to the influence of the curvature correction that has been developed for two-equation RANS turbulence models. For the T-junction considered, the activation of the curvature correction influences the head losses whereas for the two Y-junctions computed, no effect is observed. By comparing with the Y-junctions, the T-junction leads to higher head losses and helicity in the pipes downstream of the bifurcation. Compared to the current the intragroup hydraulic short circuit operation permitted, the intergroup and interplant hydraulic short circuit mode should provide better performances with possible gains until of −55% in head losses and −94% in helicity upstream of the turbines.

Estimation of Energy Storage Requirements in an Independent Power System from an Energy Perspective

Taiwan’s power system operates as an isolated grid, preventing the export of surplus energy. Excess electricity is either stored or discarded (curtailed). This study aims to estimate the energy storage requirement for the day with the most extreme electricity consumption behavior in a year without energy curtailment. Based on the installed capacity and actual power generation of renewable energy sources in 2022, this research estimates the power generation per GW of the installed capacity at full load. Integrating the government’s annual installation capacity plans, this study forecasts the annual power generation of renewable sources. Using the electrical load during the 2023 Spring Festival as a baseline and assuming an annual electricity consumption growth rate of 2%, combined with a minimum gas power output of approximately 6 GW, this study calculates the unused power generation, which represents the pumped-storage hydroelectricity and battery energy storage systems requirements for that day under a no-curtailment scenario. Considering the semi-annual adjustments in installation planning, this study’s code is open-sourced and designed to provide updated results with new planning data input, facilitating ongoing adjustments.

Zero discharge: An optimized strategy to improve the hydric deficit in the Mediterranean area by pumped hydro storage. Case study of Alicante, Spain

Alterations in annual temperature and precipitation patterns are imposing heightened strain on both urban and agricultural systems. The insufficiency of available water resources to satisfy the escalating demand necessitates a concerted effort to optimize alternative sources. In the context of agriculture, the utilization of treated water is currently executed on a sporadic basis. The elevated energy expenditures and the absence of regulatory frameworks in these systems contribute to a substantial portion of these resources being discharged into natural water bodies, or in the case of coastal municipalities, near the sea. This research endeavors to proffer a comprehensive strategy aimed at eliminating the discharge of treated water into the sea. It proposes the annual allocation of 16.7 hm3 of treated water to irrigation communities grappling with acute water deficits. The strategy, when applied to a tangible case study, ensures the reliable provision and distribution of the entire designated volume. This approach takes into account the fluctuating agricultural demands through the implementation of hybrid systems boasting an installed capacity of 15 MW. Additionally, it establishes the deployment of pumped hydro-storage reservoirs to regulate and secure the requisite energy for distribution and the osmosis process involved in treating a portion of the reclaimed water, thereby presenting a high-quality solution amenable to agricultural consumption.

Effective hydropower renewable energy source selection using fuzzy neutrosophic boundary approximate area

Small hydropower plants in rural areas are contributing to marginal economic growth and social progress, but their social sustainability assessment is under-studied. Previous studies have shown that no single renewable energy source (RES) can fully meet all sustainability criteria, despite their focus on single-user systems. Scaled renewable energy systems have varying impacts across different systems, involving technical, environmental, social, and economic aspects. This paper proposes a Triangular Fuzzy Neutrosophic Numbers (TFNNs) as an extension of the multi-attributive border approximation area comparison (MABAC) method for hybrid multi-criteria decision-making (MCDM). The proposed method is utilized to assess the selection of hydropower as the most efficient and sustainable renewable energy source for society. Pairwise comparison matrices were used to determine priority vectors and weighted averages of indicators for seven criteria. The evaluation framework analyzed five key dimensions of hydropower plants. The most stable renewable energy source, pumped storage hydropower (60.78%), was found to be followed by run-of-river hydropower (56.39%), impoundment hydropower (50.03%), storage hydropower (39.78%), and offshore hydropower (07.95%). The study offers valuable insights for policymakers and implementer on sustainable electricity solutions for hydropower. Pumped storage hydropower (PSH) improves facility efficiency by ensuring optimal operation of coal and nuclear generators without energy loss. The system can provide a stable and reliable power storage solution for renewable energy sources like wind and solar.

A real time integrated modelling and control of modified pumped storage governor-PSS damping action for random renewable penetration

The modern power system network is continuously being penetrated by asynchronous intermittent renewable generations like solar and wind sources. Also, hydro plants can be an integral part for future power generation along with pumped storage units, but their governors need to be modified to provide adequate damping torque. So, to meet these challenges a coordinated strategic control of a new two degree of freedom pumped storage hydro governor with power system stabilizer has been proposed here to damp rotor angle oscillations in power system. The modified governor can provide good regulation along with tracking of error signal and power system stabilizer is modified to provide fast response along with reduced transient and steady state error. The proposed control action is optimally coordinated by a modified differential evolution with gray wolf optimizer algorithm. A two area four machine and 39 bus modified New England hydro dominated system have been taken in this work. Proposed controller's performance has been justified by different critical oscillatory conditions as random solar and wind penetrations with time and frequency analysis. These experimentations have been conducted in MATLAB Simulink and verified with real time simulation based in OPAL-RT 4510. For optimal coordination a multi objective function has been considered here including minimization of speed and real power deviation, undershoot and overshoot with settling time. This control action is simple, easy to implement, less costly and much efficient to damp oscillations and will enhance usability of existing hydro resources.

Cavitation detection via motor current signal analysis for a centrifugal pump in the pumped storage pump station

Cavitation is quite common during centrifugal pump operation which degrades the safety and stability of the pumped storage power station. Instant prognostication of incipient cavitation and precise status monitoring of cavitation evolution can benefit accuracy of cavitation detection. In this research motor current signal analysis (MCSA) technique is applied for cavitation quantitative characterization. In order to improve the performance of MCSA for cavitation detection, the method of Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) is used for noise elimination and feature selection. IMFs irrelevant with cavitation are removed based on cavitation numerical simulation and the concurrent frequency bands in spectrograms drawn with CEEMDAN. According to the feature analysis for incipient cavitation, the signal power of IMF 3–9 is extracted to reveal incipient cavitation. The peak value in the marginal spectrum of IMF 7–8 is extracted as the indicator for the characterization of cavitation evolution. Both indicators show faster and more precise performance than previous work and can be suitable for larger-scale working conditions. Thus, CEEMDAN is beneficial for improving the feasibility and accuracy of MCSA technology. This research provides technical assistance for cavitation detection and prevention in the pumped storage power station. Index termsFailure Detection; Centrifugal Pump; Motor current signal analysis (MCSA); Cavitation characterization; Centrifugal pump; Indicator extraction.

European Green Deal + Poland + hydroelectric plants = Future?

This study considers the current state of hydropower in Poland and the legal and environmental conditions for its development. The research objective was to provide insights into the future of hydropower in Poland. An attempt was made to determine the direction of hydropower development in Poland by 2050, taking into account the requirements of the European Green Deal. The basic method used is logical argumentation, which is in turn based on a critical analysis of planning documents and scientific papers. Statistical data on the production and consumption of hydropower were also analysed. Currently, Poland’s potential for hydropower production is not being fully exploited. The main reasons for this are a lack of political support and socio-ecological issues associated with the need to take over inhabited areas or areas of high natural value. The analysis of the state of hydropower in Poland indicates that urgent intervention is required in many areas. This applies, especially, to issues of the control, modernisation and technical condition of hydropower plants and damming facilities. The potential for the development of hydropower in Poland is assessed to be very small. Environmental, socio-economic and legal conditions are unfavourable to the construction of new, large hydropower plants. The exception is pumped-storage power plants, which, acting as energy storage facilities, should in the future constitute an important element of the Polish energy system. The possibility of using defunct lignite mining pits for this purpose is indicated. It is shown that some of Poland’s former lignite mines are also conveniently located. The possible beneficial impact of building pumped-storage power plants into the water ecosystem of central Poland is emphasised.

A computational sustainable approach for energy storage systems performance evaluation based on spherical-fuzzy MCDM with considering uncertainty

Incorporating energy storage systems (ESSs) can mitigate the intermittency of renewable energy sources. There are a variety of ESSs for renewable energy with vastly different characteristics. The problem of diversity of characteristics in selecting the most appropriate ESS can be approached as a multi-criteria decision-making (MCDM) problem. This research evaluates sustainable ESSs through a case study in Egypt. A sustainable computational approach is presented through which experts can use verbal expressions to express their opinions in determining the priorities of the dimensions that affect the selection of ESSs. Determining the appropriate energy storage system requires consideration of several main dimensions such as the technology dimension, environmental dimension, economic dimension, and social-political dimension and, in addition to the sub-indicators. Hence, this research applies a hybrid MCDM approach that deals with different indicators and characteristics. Also, uncertainty in applying the proposed approach was dealt with by a spherical fuzzy (SF) environment and by using the spherical fuzzy numbers (SFNs). At first, the SF analytical hierarchy process (SF-AHP) method was used to assess the priorities of the four main dimensions and their sub-indicators. Then, the SF mixed aggregation by comprehensive normalization technique (SF-MACONT) was applied to evaluate and rank the ESSs selected for analysis through research. An illustrative case study was presented that included seven ESSs out of the eighteen systems listed in the research to confirm the feasibility of the developed approach. Sensitivity analysis was carried out by changing some parameters like λ, μ, δ, and ϑ based on the SF-MACONT method and changing the weights of some main dimensions. A comparative analysis with some MCDM approaches was conducted to show the advantages of the developed approach through its flexibility and built-in parameters. The findings show that the technology dimension is the most influential in choosing a sustainable ESS, while the economic dimension is the least influential. Also, the results of the evaluation and ranking of the seven selected ESSs indicate that the "Pumped Hydro" system is the most suitable system for energy storage in Egypt.

Determining Digital Representation and Representative Elementary Volume Size of Broken Rock Mass Using the Discrete Fracture Network–Discrete Element Method Coupling Technique

Obtaining the digital characterization and representative elementary volume (REV) of broken rock masses is an important foundation for simulating their mechanical properties and behavior. In this study, utilizing the broken surrounding rock of the main powerhouse at the Liyang pumped storage power station as an engineering background, a three-dimensional fracture network generation program is first developed based on the theories of discrete fracture network (DFN) and discrete element method (DEM). The program is then integrated with a distinct element modelling platform to generate equivalent rock mass models for broken rock masses based on the DFN–DEM coupling technique. Numerical compression tests are conducted on cylindrical rock specimens produced using the proposed modelling approach, aiming to determining the REV size of the target rock masses at the Liyang power station. A comparative validation is also performed to examine the REV result obtained from the proposed approach, which adopted a REV measuring scale index (RMSI) to determine the REV size. Results indicate that the organic integration of DFN simulation techniques and DEM platforms can effectively construct numerical models for actual broken rock masses, with structural surface distributions statistically similar to the real ones. The results also show that the REV size of the investigated rock masses determined by the cylindrical rock models is 5 m × 10 m, which aligns with the size determined by the cubic rock models, as the target cubes show the same height as the cylindrical specimens. This study provides a model and parameter basis for the numerical calculation of the mechanical behavior of broken rock mass.

Modelling a Decarbonization Agenda for Bembibre’s Industrial Park

The design of the Sustainable Strategy Agenda for the Bembibre industrial zone in the Bierzo region employing the Open-Source Energy Modeling System (OSeMOSYS) is presented. This municipality, which has been affected by the collapse of the coal mining industry, is at the epicentre of the reindustrialization and Just Transition (none left behind) initiatives of the Spanish government. Among the challenges to be tackled are the zone's entire decarbonization by 2030, the incorporation of circular economy initiatives, and the development of quality jobs that attract and retain new residents. To facilitate decision-making, different roadmaps have been evaluated, including the repurposing of an old coal mine galley as a reverse hydro storage system, the deployment of enterprises dedicated to the recycling of solar panels, and the incorporation of second-life batteries from electric vehicles as energy storage. Among the scenarios evaluated, the most complex turns out to be the most interesting. With an initial outlay of 190 M€, it incorporates a 210 MW photovoltaic park linked to a mixed storage system comprised of 0.25 GWh of reverse hydraulic systems and 68MWh of second life reconditioned batteries. About 850 jobs in the implementation stage and 70 more permanent in the exploitation phase are envisaged.

Rapid Assessment of Effectiveness Pump Storage Power Plant of Jatiluhur Reservoir

The reliable discharge calculation for forecasting discharge entering the Jatiluhur Reservoir uses the Thomas Fierring method. In this study, a rapid assessment was carried out on the effectiveness of the PSPP in the Jatiluhur Reservoir in 2040 by also considering changes in water demand downstream of Jatiluhur in 2040. A pumped storage power plant (PSPP) is a renewable energy storage medium for electrical energy. A rapid assessment was carried out on the calculation of the energy and volume produced with the operational hours, the condition of the reservoir being full (+ 106.5 m) and the condition of the reservoir approaching the minimum operating limit (+ 90 m). Based on the study’s results, PSPP at the Jatiluhur Reservoir will produce additional electrical energy of 2,180,763 kWh with a water volume requirement of 6,669,000 m3/day and operational is 2,85 hours. The operational of PSPP will reduce the Water High Level (WHL) of the Jatiluhur Reservoir by 0.12 m (full-time condition) and 0.15 m (minimum operating limit reservoir condition). With the PSPP, it is known that the Jatiluhur Reservoir can still operate normally so that the PSPP can increase electricity production without significantly reducing the WHL and volume of the Jatiluhur Reservoir.

The influence of the planned Solina-Jawor pumped storage power plant on the operating regime of the Solina-Myczkowce power plant

The article presents an extended model of the Solina-Myczkowce pumped storage power plant with the designed new reservoir and Jawor power plant. Different design cases for the size of the reservoir located on Mt. Jawor were considered. In building the model, a modular approach was used to clearly distinguish elements of the model. In order to capture seasonal changes in both hydrological conditions and power demand values, a period of 365 days was assumed for the simulations. The simulations assumed the form of criteria defining on/off moments and defining the turbine/pump turbine operating regime using the daily variation of energy prices. All constraints arising from the physical parameters and limitations of the cascade facilities as well as those arising from the provisions of the current Water Management Manual for the Solina-Myczkowce cascade were taken into account. The model was designed and executed using the Matlab-Simulink interface. The developed model, assuming various solutions of the additional Jawor-Solina pumped storage power plant, allows multivariate analysis of the effects, both in the sphere of electricity production and financial . The flexible design of the model is a proposal with the help of which it is possible to develop and test decision-making mechanisms in the energy and financial area of cascade operation. Expansion of the energy cascade with a new element of the pumped storage power plant affects the functioning in its current form of the Solina-Myczkowce PSPS. The results show the directions of changes that should be made in the operating strategy of such an expanded energy complex. The analyses are supported by a number of charts and a commentary.

Innovation and Application of Reliability-Centered Maintenance Technology for Pumped Storage Power Plant

With the increasing capacity and scale of pumped storage power plant, the maintenance management and resource input of system equipment are continuously increasing. Exploring and establishing a system engineering method that balances safe production and maintenance resource input has become an important issue that enterprises urgently need to solve. Based on the reliability-centered maintenance (RCM) technology, this paper combines the characteristics of pumped storage unit operation and maintenance management and years of maintenance practice experience to improve and innovate the RCM technology method, forming a “reliability-centered pumped storage unit maintenance strategy optimization technology method” applicable to pumped storage power generation units. This technology method has been applied on the system equipment of pumped storage power generation unit. It shows the application of this technology method has made significant contribution to optimizing equipment maintenance strategies, reducing maintenance workload and the overhaul time.

Design of wound vegetation restoration measures for upper and lower reservoir connecting road project of pumped storage power station in northwest cold and arid regions

Taking a pumped storage power station in the northwest cold and arid regions as an example, this paper summarizes the construction technology and method of wound vegetation restoration in the upper and lower reservoir connecting road project of pumped storage power station in the northwest cold and arid regions, as well as the system of measures including the selection of suitable plants, the design of soil covering engineering, the design of plant measures and the construction technology. The soil covering engineering and plant measures were designed according to different wound types. The soil preparation of the Yurian pit and the ridge outside the pit were constructed with planting bags, arbor and shrubs were planted inside the pit, Picea asperata Mast. was selected for arbor and Juniperus sabina L. for shrubs, and forest vegetation blanket was used on the upper slope with a gentle slope, and shrubs and grass seeds were mainly planted with Poa annua L., Stipa capillata L. and Artemisia frigida Willd. The above vegetation restoration measures were designed. It greatly reduces soil and water loss in the reservoir area, improves vegetation coverage in the reservoir area, and enriches plant diversity, making the wound surface of the upper and lower reservoir connecting road of pumped storage power station gradually restore to the natural environment plant community state before the destruction.

Практическая реализация инженерной методики определения напряженного состояния в горизонтальных сечениях железобетонных подпорных стен

Retaining walls made of reinforced concrete are widely used in hydraulic engineering and transport construction. Since their rear faces are covered with ground filling, it seems difficult to control the stressed state of the rear working fittings, which in some cases led to deviations in the work of structures from the project. In this article, corner type retaining walls are considered. The purpose of the work was to develop and test an engineering technique for determining the stress state in horizontal sections of retaining walls made of reinforced concrete. In the framework of this work, studies were conducted on the structures of reinforced concrete retaining walls that interact with the soils of the base and backfill. At the same time, using the provisions of structural mechanics and the theory of reinforced concrete, an engineering technique was developed that allows calculating the stress state of reinforced concrete retaining walls along horizontal sections. To test the proposed calculation methodology, the in-situ data of instrumental surveys of the operated lower retaining walls of the PSPP water intake (pumped storage power plant) were used on the basis of the “reinforcement unloading” method in relation to the facing structural reinforcement of the walls. The developed method was practically implemented to assess the effective tensile stresses in the rear working reinforcement, as well as the compressive stresses in the concrete of retaining walls.

Application and Development of Hydraulic Steel Structure Safety Information Management System in Pumped Storage Hydropower

In the context of the current energy structure transition and the rapid advancement of clean energy, the reliability of hydraulic steel structure equipment plays a crucial role in the stable operation and efficiency improvement of pumped storage hydroelectric power stations. With technological advancements, strengthening the digital management of hydraulic steel structures has become a focal point in the industry's development. This paper takes the "JinZhi" system developed by the PowerChina HuaDong Engineering Corporation Limited as an example to deeply explore the practical application of hydraulic steel structure safety information management system and its significant role in enhancing operational efficiency and safety. By analyzing industry development trends, the paper reveals the challenges and potential opportunities encountered during digital transformation and proposes targeted recommendations for future development direction. The research demonstrates that the integrated application of information technology can effectively improve the management quality and safety level of hydraulic steel structures, ensuring the efficient and stable operation of power stations, and providing valuable insights for similar industries aiming to achieve digital transformation.

Optimal Energy Management of a Hybrid System Composed of PV, Wind Turbine, Pumped Hydropower Storage, and Battery Storage to Achieve a Complete Energy Self-Sufficiency in Residential Buildings

Optimal Energy Management of a Hybrid System Composed of PV, Wind Turbine, Pumped Hydropower Storage, and Battery Storage to Achieve a Complete Energy Self-Sufficiency in Residential Buildings