Operation Of Power Station Research Articles

Vibration control on coupled unit-plant structure of pumped storage power station during sudden load-up process

The versatile regulatory capacity of pumped storage power station (PSPS) stems from the reversible pumped turbine unit switching between multiple operating conditions. Nevertheless, the unit and plant structure experience heightened vibrations owing to the intricate interplay of hydraulic, electrical, and mechanical excitations during transition processes, and the vibration responses fluctuate as operating conditions shift, posing a significant challenge to the safety and high quality operation of power station. To tackle the practical engineering issue, this paper delves into the sudden load-up scenario in power generation situation of pumped turbine, leveraging a finite element model encompassing the coupled hydraulic-mechanical-electrical-structural system (HMES) of PSPS and a mathematical model of unit shaft system, the impacts of dynamic loads induced by various vibration source on the unit and plant structure during transient condition, are meticulously analyzed and discussed through numerical simulations. Additionally, the magnetorheological damper (MRD), is incorporated into the PSPS to explore the effectiveness of MRD in controlling transient vibration in the interconnected unit-plant structure. The results indicate that the system parameters and associated load excitations undergo rapid fluctuations during the load-up process, bringing about noticeable oscillations in vibration amplitudes of rotor and turbine. The floors and fan hood of plant are the most vulnerable areas in terms of structural strength, with associated displacement amplitudes being most noticeable. The incorporation of MRD proves to be highly effective in mitigating the unsteady vibrations in both the unit and the plant structure during load-up course, as well as optimizing the motion patterns of rotor and turbine, promoting a notable reduction in frequency amplitudes of spectrum. Moreover, the maximal transient displacement amplitude of unit is significantly diminished, with the rotor experiencing a decrease of approximately 79%, while the amplitude of turbine declines by 16%. The displacement fluctuation ranges of the plant structure are observably diminished, and the complex frequency components of vibration signal are efficiently controlled. The transient vibration characteristics of the coupled unit-plant structure and the damping behavior of MRD during the transition process are unveiled by the research findings in this paper, which can offer valuable insights for the stability assessment and the research on vibration management of HMES for PSPS under the unsteady operation conditions.

Research on performance ratio composition and standard energy efficiency ratio correction method of photovoltaic power station

The performance ratio (PR) of the system is used to quantify the power generation efficiency of the photovoltaic power generation system. The size of the index is affected by many factors. After the environmental impact is compensated, the standard energy efficiency ratio (PRstc) of the system is obtained. PRstc is an important index for evaluating the power generation efficiency of photovoltaic power stations. Improving the accuracy of PRstc is conducive to improving the state evaluation and analysis capabilities of power stations, providing a theoretical basis for comparative analysis of photovoltaic power stations in different regions, and improving the scientific operation and maintenance of power stations. The PRstc calculation method of the industry standard NB / T 10394-2020 does not consider the influence of the change of the power temperature coefficient of the component and the weak light response of the photovoltaic cell, which ultimately leads to the calculation result less than the actual value. In order to reduce the error in the calculation of PRstc, the mathematical relationship between PR and power loss of photovoltaic power station is discussed. The calculation method of power loss caused by the change of environmental factors is proposed, and the PRstc is calculated by using the variation. Finally, the PRstc is calculated according to the actual operation data of photovoltaic power station, and compared with the calculation method of industry standard NB / T 10394-2020. The results show that when the total irradiation dose is high, the difference between the two PRstc values is less than 2 %. When the total irradiation is low, the calculation result is larger than that of the standard method, and the difference between the two increases with the decrease of the total irradiation. Due to the consideration of the change of power generation caused by the characteristics of photovoltaic modules, the error caused by the change of power temperature coefficient and weak light response of modules is reduced, which is more advantageous than the calculation method of industry standard.

Developments of AI-Assisted Fault Detection and Failure Mode Diagnosis for Operation and Maintenance of Photovoltaic Power Stations in Taiwan

Developments of AI-Assisted Fault Detection and Failure Mode Diagnosis for Operation and Maintenance of Photovoltaic Power Stations in Taiwan

A monitoring and early warning platform for energy storage systems based on big data analysis

This article focuses on the safe operation of lithium battery energy storage power stations and develops a data monitoring and safety warning platform for energy storage systems. The background, architecture, implementation methods, and main functions of the platform development are introduced in sequence. This platform significantly improves the safety of energy storage stations by implementing active safety monitoring and early warning, which is of great significance for the large-scale application and promotion of lithium battery energy storage stations.

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.

Research on Anomaly Identification of PV Power Station Operation Data Based on Fuzzy Association Rules

Research on Anomaly Identification of PV Power Station Operation Data Based on Fuzzy Association Rules

Long-term forecasting methods of dates of ice break-up and disappearance at the Dnipro Cascade Reservoirs by teleconnection indicators

Long-term forecasting of the ice regime at the Dnipro Cascade Reservoirs is very important, first of all, for the operation of hydroelectric power stations. In addition, such forecasts also ensure the work of other sectors of the economy, namely shipping, fisheries, municipal engineering, etc. At present, the Department for hydrological forecasting of the Ukrainian Hydrometeorological Center uses techniques developedin the middle and in thesecond half of the 20th century to compile long-term forecasts and advices about the ice regimeof water bodies of Ukraine. These techniqueswere developed only for rivers;for reservoirs,they are currently lacking.
 The main objective of our research is to develop methods for long-term forecasting of ice break-up and disappearance at the Dnipro Cascade Reservoirs by teleconnection indicators. The research was based on the recordsfor 35 water gauges located on 6 reservoirs of the Dnipro Cascade, including the destroyed Kakhovka reservoir. The dates of the ice break-up and disappearance were used for the period from the beginning of observations at each water gauge to 2020. Moreover, the teleconnection indicators were used, namely 34 atmospheric indices, sea surface temperature indices, teleconnection indices and patterns determined by the National Weather Service (NWS) of the National Oceanic and Atmospheric Administration of United States of America (NOAA USA).
 Methods of the long-term forecasting of the ice break-up and disappearance at the reservoirs of the Dnipro Cascade have been developed by searching for the best correlation or regression relationship between dates and teleconnection indicators. The probable of accepted errorsof the developed methods are in the range of 62—71 %, which corresponds to satisfactory method quality that makes it possible to recommend them for use.

Location of Mountain Photovoltaic Power Station Based on Fuzzy Analytic Hierarchy Process—Taking Longyang District, Baoshan City, Yunnan Province as an Example

Site selection is a key link in the early stage of constructing a photovoltaic power station and providing accurate guidance for the development of such stations. Taking Longyang District, Baoshan City, Yunnan Province, as an example, this article utilizes land-use status data from the third national land survey. The study focuses on five land-use types: idle land, bare land, shrub land, forest land, and another grassland, while excluding interfering land types such as construction land, ecological conservation areas, and cultivated land. Thirteen factors including terrain, weather, environment, and neighboring resources are considered. By employing the fuzzy analytic hierarchy process, a site selection model is constructed to analyze the suitability of photovoltaic power station locations. This study emphasizes the influence of geological disaster factors when selecting environmental factors. Given the high frequency of geological disasters in mountainous areas, these factors significantly affect the safety of later-stage photovoltaic power station operations. Previous research has paid less attention to this factor. The results indicate a high level of suitability for photovoltaic site selection in Longyang District, Baoshan City, with suitable, moderately suitable, and unsuitable areas accounting for 20.09%, 34.14%, and 45.77%, respectively. Previous studies have lacked sufficient validation of site selection outcomes. In this research, validation is conducted using areas where photovoltaic power stations have already been established and are under construction within the region. The accuracy of this site selection method is found to be 92.78%. The aim is to provide a scientific reference for site selection in mountainous areas with photovoltaic power station construction needs.

ОПТИМИЗАЦИЯ ВОДОХОЗЯЙСТВЕННОГО КОМПЛЕКСА НА ОСНОВЕ СИНЕРГЕТИЧЕСКОЙ ОЦЕНКИ СТОИМОСТИ ГИДРОРЕСУРСА

The purpose of this article is to solve the multicriteria problem of optimizing the operation of hydroelectric power stations based on the selection of the optimal activities of the water-chemical complex (water management complex). The work has developed a universal methodology that combines the optimization method and the theory of marginal utility assessment. The proposed approach is based on the construction and analysis of a matrix of contradictions between participants in the water management complex and the use as the main criterion of the minimum deviation of the actual volume of water consumption (consumption) by participants in the water-chemical complex from its optimal value. The work also analyzes the conflicting interests of the water and chemical complex participants by comparing the requirements for issuing guaranteed power of hydroelectric power plants and ensuring guaranteed navigation depths as the most significant participants in the water-energy complex based on the use of Pareto optimization - the optimal set. Using the example of the Novosibirsk hydroelectric power station and water-chemical complex, it is expected to obtain an assessment of the economic effect from the implementation of the proposed criterion and the developed methodology for optimizing the water-chemical complex. Based on the results of implementing the developed approach at the Novosibirsk HPP, it was possible to find the optimal regime for managing the capacity of the HPP reservoir and achieve an increase in the level of the upper and lower pools.

Study on the influence of electrode materials on energy storage power station in lithium battery

Lithium batteries are promising techniques for renewable energy storage attributing to their excellent cycle performance, relatively low cost, and guaranteed safety performance. The performance of the LiFePO4 (LFP) battery directly determines the stability and safety of energy storage power station operation, and the properties of the internal electrode materials are the core and key to determine the quality of the battery. In this work, two kinds of commercial LFP batteries were studied by analyzing the electrical properties and material properties of the electrodes. After performing the rate and cycle performance tests of the battery cell, differential scanning calorimetry, scanning electron microscope, x-ray diffraction, and inductively coupled plasma were used to explore the performance of electrode materials to establish the correlation between the battery performance and the electrochemical reaction law of the internal materials and further to judge the influence of the key material properties on the battery performance. This work opens up an avenue for technical supervision of energy storage power stations.

Research on the control strategy of DC microgrids with distributed energy storage

As a supplement to large power grids, DC microgrids with new energy access are increasingly widely used. However, with the increasing proportion of new energy in DC microgrids, its output fluctuations directly affect the overall stability of the microgrids. Distributed energy storage can smooth the output fluctuation of distributed new energy. In this paper, an AC-DC hybrid micro-grid operation topology with distributed new energy and distributed energy storage system access is designed, and on this basis, a coordinated control strategy of a micro-grid system based on distributed energy storage is proposed. To maintain the voltage stability of the DC bus and make each station have the power-sharing ability, the AC/DC flexibly interconnected converter should adopt two control strategies. The power can flow bidirectional in the power scheduling and distribution of the energy storage station; At the same time, different power distribution schemes will generate different scheduling costs. To optimize the operation of energy storage power stations, an improved particle swarm optimization algorithm is adopted in this paper to optimize the scheduling task allocation scheme. The optimization objective is the lowest scheduling cost, to realize the optimal scheduling of energy storage power stations. In this paper, based on a Matlab/Simulink environment, a microgrid system based on an AC-DC hybrid bus is built. The simulation results verify the effectiveness of the proposed microgrid coordinated control strategy.

Optimizing pumped-storage power station operation for boosting power grid absorbability to renewable energy

Optimizing peak-shaving and valley-filling (PS-VF) operation of a pumped-storage power (PSP) station has far-reaching influences on the synergies of hydropower output, power benefit, and carbon dioxide (CO2) emission reduction. However, it is a great challenge, especially considering hydro-wind-photovoltaic-biomass power inputs. This study proposed a novel optimization operation framework for a PSP station driven by the PS-VF operation for boosting power grid absorbability to renewable energy inputs. An optimization operation model based on a grasshopper optimization algorithm was developed to minimize the residual load volatility. A PSP station in the Hunan Province of China constituted the case study, and the practical operation scheme formed the benchmark. The findings underscore the effectiveness of the proposed approach in fostering remarkable synergy, evident in substantial improvement rates of 61% for power output, 58% for power benefit, and 62% for CO2 emission reduction compared to the practical operational scheme. This study not only furnishes valuable scientific and technical backing for the PS-VF operation of the PSP station, enhancing the interplay between hydropower generation, financial benefits, and CO2 reduction, but also provides policymakers with well-informed strategies that consider potential load volatilities and advantages. These strategies are geared towards enhancing the power grid's capacity to assimilate hydro-wind-photovoltaic-biomass power inputs, aligning with the goals of sustainable renewable energy development.

Optimal Dispatch of Concentrating Solar Thermal Power (CSP)-Wind Combined Power Generation System

The random nature of renewable energy leads to the instability of the balance state of the power grid, and the frequency and voltage of the grid also fluctuate. Considering that wind energy and solar thermal power generation can complement each other in terms of temporal output power, the heat storage system of the solar thermal power station is used to regulate the joint operation of the solar thermal power station and wind power generation, and an optimal scheduling method for promoting new energy consumption of solar thermal power station is proposed. Based on the solar thermal-wind combined power generation system, the method considers the operating characteristics and constraints of each unit and uses the MATLAB optimization toolbox to simulate and verify the IEEE-14 node system. The results show that the participation of wind power grid-connected time thermal power stations can alleviate the pressure of rapid output adjustment of traditional units and can ensure the economy of the system, and the operating cost is reduced by 51.5%. The curtailment air volume was reduced from the original 2.5015 MW to 0.83015 MW, maximizing new energy consumption.

Influence of Construction Period of Bridge Across Reservoir on Operation of Adjacent Power Station

The influence of the construction period of the bridge project across the reservoir on the adjacent power station includes not only the direct impact on the hydropower hub but also the impacts on the reservoir area, flood discharge, power station head, water diversion and sediment prevention, power generation operation, and other factors. In this paper, from the aspects of the power station operation, an evaluation index for the influence of the construction period of a bridge across a reservoir on the adjacent power station is developed, and an evaluation system is constructed. Based on the constructed evaluation system, the influence of the bridge construction period on the adjacent power stations is analyzed. This evaluation system provides a reference for the impact assessment of cross-reservoir bridge engineering on adjacent hydropower stations.

Permeability Tests and Numerical Simulation of Argillaceous Dolomite in the Jurong Pumped-Storage Power Station, China

Due to its poor hydro-physical properties and other characteristics, argillaceous dolomite is susceptible to seepage failure under high water pressure, affecting the seepage stability of a rock mass. To ensure the safety of the project, when the argillaceous dolomite is present, it is necessary to study the conditions pertaining to its seepage failure. Taking the argillaceous dolomite of Jurong Pumped Storage Power Station as the research object, the spatial distribution, occurrence, scale, degree of weathering, and mechanical and hydrogeological characteristics of the argillaceous dolomite were studied. Through on-site water pressure tests and laboratory variable head tests, the permeability characteristics of argillaceous dolomite were analyzed, and the hydraulic conductivity of the argillaceous dolomite in the upper reservoir and underground powerhouse areas was quantified. The argillaceous dolomite specimens were collected, and seepage failure tests were conducted to determine the critical water pressure for its seepage failure. Based on the results of the laboratory tests, a numerical model of groundwater flow was established. By changing the water level of the upper reservoir and the measures of the anti-seepage and drainage, the seepage stability of the argillaceous dolomite was discussed. The actual water pressure of argillaceous dolomite in the underground powerhouse area was identified during the operation of the Jurong pumped-storage power station. The calculations show that when fully enclosed anti-seepage and drainage measures are taken for the underground powerhouse, the maximum head of water is 98 m, which is lower than the critical water pressure of seepage failure for the argillaceous dolomite. Therefore, no seepage failure will occur. The results provide a scientific basis for the anti-seepage and drainage design of the underground powerhouse area.

Optimal control of combined heat and power station operation

Combined heat and power stations have become one of the most utilized units of district heating systems. These stations usually contain several boilers for burning fossil fuels and renewable resources used for heating up steam, which can be used either for residential and commercial heating or electricity generation. To ensure efficiency, a boiler should either run continuously (for at least a given period) on a power output higher than a given threshold or switch off. The optimal control of the plant operations should combine an efficient setup for the turbine and boilers in operation, reflecting the demand for steam and the price of electricity, and a schedule that describes which boilers should be in operation at a given time. This paper proposes a method for optimal control of combined heat and power station operation for a given time horizon. The method is based on a two-level approach. The lower-level models correspond to finding the optimal setup of the combined heat and power station parameters for an hourly demand for different kinds of steam. The upper-level model corresponds to the optimal schedule of the operations of the individual boilers, which is planned for the entire time horizon. The lower-level model is modeled as a mixed-integer linear programming problem and is solved using parametric programming. A dynamic programming algorithm solves the upper-level model with a rolling horizon. The validity of the proposed method and its computational complexity for different granularity of the time horizon, different ranges of the parameters, varying demand for various kinds of steam, and varying electricity prices are investigated in a case study. The presented approach can be readily applied to other control problems with a similar structure.

Mixed Multi-Pattern Regression for DNI Prediction in Arid Desert Areas

As a crucial issue in renewable energy, accurate prediction of direct normal solar irradiance (DNI) is essential for the stable operation of concentrated solar power (CSP) stations, especially for those in arid desert areas. In this study, in order to fully explore the laws of climate change and assess the solar resources in arid desert areas, we have proposed a mixed multi-pattern regression model (MMP) for short-term DNI prediction using prior knowledge provided by the clear-sky solar irradiance (CSI) model and time series patterns of key meteorological factors mined using PR-DTW on different time scales. The contrastive experimental results demonstrated that MMP can outperform existing DNI prediction models in terms of three recognized statistical metrics. To address the challenge of limited data in arid desert areas, we presented the T-MMP model involving combined transfer learning and MMP. The experimental results demonstrated that T-MMP outperformed MMP in DNI prediction by exploiting the significant correlation between meteorological time series patterns in similar areas for data augmentation. Our study provided a valuable prediction model for accurate DNI prediction in arid desert areas, facilitating the economical and stable operation of CSP plants.

Improving the economic and environmental benefits of the energy system: A novel hybrid economic emission dispatch considering clean energy power uncertainty

New energy power generation plays an important role in adjusting energy structure, reducing environmental pollution, and promoting sustainable social development. However, new energy power generation represented by solar and wind power has significant volatility, meanwhile, the wind and solar curtailment caused by uncertainty reduce utilization rate. In this context, considering the impact of uncertainty in new energy generation on system scheduling and developing new algorithms that can efficiently solves such complex scheduling problems are necessary. Therefore, this study constructed a hybrid dynamic economic emission model (HDEED) with the new energy generation penalty mechanism, and proposed a novel multi-objective tunicate swarm algorithm (MTSA)-based solution method. First, based on the unit operation characteristic equations, considering wind and solar power uncertainty, the HDEED model with the new energy generation penalty mechanism was constructed. Second, on the basis of the single objective tunicate swarm algorithm, MTSA algorithm was proposed by adding the running operators, and the feasibility of the proposed algorithm was verified. The test results showed that the Pareto fronts obtained by MTSA algorithm presented good distribution and diversity compared with existing algorithms. Finally, the proposed model and algorithm were proved by modified test system, meanwhile, the impacts of clean energy power on system operation stability, economic and environmental benefits were discussed. The results revealed that the penalty costs caused by uncertainty were higher than the operation and maintenance costs of new energy power stations, which accounted for about 2.1% of the total costs. The outcomes obtained in this study contribute to improving the utilization rate of clean energy and promoting the sustainable development of energy system.

ОПТИМИЗАЦИЯ РЕЖИМОВ РАБОТЫ ГЭС НА ОСНОВЕ ТЕОРИИ ПРЕДЕЛЬНОЙ ПОЛЕЗНОСТИ И ОЦЕНКИ СТОИМОСТИ ГИДРОРЕСУРСА

The purpose of this article is to solve the problem of optimizing the operation of a hydroelectric power station based on the theory of marginal utility and assessing the cost of a hydro resource, taking into account the characteristic modes of operation of a hydroelectric power station. In this work, a universal method, which combines an optimization method and a method for assessing marginal utility. The method developed by the authors involves use the adequate representation of the incremental rate characteristic and the determination of the cost of the hydro resource for the control of the operating modes of the HPP. Using the example of the Novosibirsk HPPs and TPPs, an assessment of the energy efficiency, proposing the concept of a developed methodology for determining the price of water for HPPs, will be obtained. Based on the results of the implementation of the developed approach at Novosibirsk HPPs, the electricity sales price competitive electricity market can be matched with the electricity sales price generated at TPP, which will be approximately 370 ¢/kWh

Analysis of Hydrogen Production Potential from Water Electrolysis in China

Currently, the cost of electricity for electrolysis of producing hydrogen is about 70–90% of the total cost. Scientists predict that the share of renewable energy in total energy is expected to reach about 70% in 2050, as the cost of wind photovoltaic power generation in China is as low as 0.13¥/(kW·h), and that the use of renewable energy sources, mainly photovoltaic and wind power, of producing hydrogen can effectively reduce the cost of electricity. Meanwhile, with the improvement of technology, the cost of an electrolyzer used in proton exchange membrane hydrogen production technology can be reduced by about 50%, which will reduce the cost of hydrogen production by more than 20%. According to the distribution of electricity resources in each region of China, the project construction of renewable energy power generation and proton exchange membrane hydrogen production can be reasonably carried out. A long-distance hydrogen transmission system can be established to provide guaranty for the establishment and operation of urban hydrogen power stations using a combination of renewable energy and long-distance hydrogen transmission systems. This paper provides a reference for the industrial development and policy direction of hydrogen production by water electrolysis.