Hydroelectric Power Research Articles

Evaluation of Forces on the Needle for Regulation of Pelton Turbine Injector

Abstract In hydropower plants, the Pelton turbine is a commonly used hydraulic turbine where flow is regulated with a dual mechanism of needle and deflector. The needle is controlled by a servomotor and governor system, where the flow rate varies by adjusting the needle strokes. The needle is operated under the hydraulic force caused by the high-water pressure inside the injector acting on the needle surface. The objective of computing the force balance in a Pelton injector is to determine the force to be supplied by the servomotor. The closing trend is crucial to design the injector for safe operation during an emergency. In this study, the function of the needle and nozzle curve generalizes the variable needle surface area, allowing the geometric properties of the nozzle and needle to be suitable for the needle force evaluation. The single-axis force transducer, which is mounted on the needle rod, has been used in the experimental method for determining the needle forces. The experimental findings are compared to analytical calculations and serve as validation for the accuracy and reliability of the computed results obtained through the analytical approach.

The role of inter-island transmission in full decarbonisation scenarios for Indonesia’s power sector

Indonesia has large renewable energy resources that are not always located in regions where they are needed. Sub-sea power transmission cables, or island links, could connect Indonesia’s high-demand islands, like Java, to large-resource islands. However, the role of island links in Indonesia’s energy transition has been explored in a limited fashion. Considering Indonesia’s current fossil fuel dependency, this is a critical knowledge gap. Here we assess the role of island links in Indonesia’s full power sector decarbonisation via energy system optimisation modelling and an extensive scenario and sensitivity analysis. We find that island links could be crucial by providing access to the most cost-effective resources across the country, like onshore photovoltaics (PV) and hydropower from Kalimantan and geothermal from Sumatera. In 2050, 43 GW of inter-island transmission lines enable 410 GWp of PV providing half of total generation, coupled with 100 GW of storage, at levelised system costs of 60 US$(2021)/MWh. Without island links, Java could still be supplied locally, but at 15% higher costs due to larger offshore floating PV and storage capacity requirements. Regardless of the degree of interconnection, biomass, large hydro, and geothermal remain important dispatchable generators with at least 62 GW and 23% of total generation throughout all tested scenarios. Full decarbonisation by 2040 mitigates an additional 464 MtCO2e compared to decarbonisation by 2050, but poses more challenges for renewables upscaling and fossil capacity retirement.

Research on fault diagnosis of main equipment based on watershed power production data center

Abstract With the development of intelligent hydroelectric power stations and centralized control centers, water and hydropower development companies in various river basins have constructed power production data centers, establishing standardized and normalized data models and connecting the underlying system channels. Based on the power production data center, this paper constructs a unified data model for monitoring the main equipment and, in response to the shortcomings of the existing equipment alarm mode, analyzes the advantages of expert knowledge and intelligent diagnostic methods. It establishes a comprehensive diagnostic system for the main equipment of power stations, providing multi-level and multi-perspective diagnostic reference opinions. This system is of great significance for promoting the development of intelligent hydroelectric power and centralized control. Finally, taking the operating condition data of a mixed-flow turbine generator unit as an example, the effectiveness of the comprehensive diagnostic model is analyzed and verified.

RATIONALE FOR THE TECHNOLOGY OF PROTECTING THE METAL SURFACE IN THE FLOW PATH OF A HYDRAULIC TURBINE TO REDUCE CAVITATION WEAR

The relevance of the problem is due to the significant scale of cavitation destruction of hydraulic turbines of many operating hydroelectric power stations and the high economic costs of major repairs of hydraulic units. Methods for restoring surfaces damaged by cavitation in the flow path of hydraulic turbines at hydroelectric power stations are considered. Based on a review and comparison of existing technologies, recommendations are made that significantly increase the periods between major overhauls of hydraulic turbine parts. It has been shown that material damage due to cavitation can be minimized by using cavitation-resistant materials. A feasibility study for a combined method of repairing a hydraulic unit is presented.

Morphological and ecological traits of the rigid-leaved water crowfoot Ranunculus subrigidus (Batrachium, Ranunculaceae) in the Yenisei River (Siberia, Russia)

The study of water crowfoots in the Yenisei River confirmed the wide distribution of recently restored rigid-leaved North American-North Asian species Ranunculus subrigidus instead of previously mentioned European R. circinatus. The species identification as R. subrigidus was confirmed by the analysis of the ITS region nucleotide sequence and morphological data. In contrast to literature data, samples of this species collected in the Yenisei did not have sessile leaves, in half of the samples, the length between first and second bifurcation was greater than the maximum of 0.2 cm previously described for the species, in some of the samples, internodes were shorter than the leaves, also different types of pubescence were observed on plant shoot parts. The conditions under which this species grows in the Yenisei River differ from the previously reported ones, primarily, in such parameters as the water hardness and the flow regime. At the city of Krasnoyarsk, seasonal development of R. subrigidus is affected by the Krasnoyarsk Hydroelectric Power Plant. The paper presents a geobotanical description of the Yenisei River plant communities dominated by and containing R. subrigidus.

Assessing the impact of climate change and water scarcity of ferronickel production in Indonesia: A life cycle assessment approach

In Indonesia, emissions from coal-fired steam power stations are the greatest environmental concern of the nickel industry. Prior researches have exclusively focused on carbon dioxide (CO2) emissions. Meanwhile, this study includes CO2 fossil and CO2 biogenic emissions as well as CO2 absorption by plants into its assessment of the climate change consequences associated with ferronickel production in Indonesia. The objective of this study is to evaluate the potential impacts of climate change and water scarcity on the nickel industry in Indonesia by implementing various power facility scenarios. The methodology chosen for this study was Attributional Life Cycle Assessment (ALCA). The impact of climate change can be reduced by 38.9 %, or from 99,024.7 to 60,522.2 kg CO2 eq/t, if coal fuel is replaced with biomass fuel in steam power plants. By replacing steam power stations fuelled by coal with hydroelectric facilities, the impact of climate change can be reduced by 96 %, from 99,024.7 to 3,993.7 kg CO2 eq/t. This results in a 12.5 % decrease in water scarcity, from 100.3 to 89.1 m3 H2O eq/t. In the nickel industry, hydroelectric power plants are more effective at mitigating climate change than steam power plants powered by coal or biomass.

Hidden Flows: Hydropower and the Rhythms of Development on the Mekong

The Xayaburi Hydroelectric Power Project entered operation in October 2019. After this the Mekong started to behave strangely—the water ran blue and clear instead of red and silty, and the great backflow of the river into Cambodia's Tonle Sap Lake arrived off schedule or, at times, threatened to not arrive at all. Villagers who had remained ambivalent or apathetic about hydropower issues suddenly found themselves facing a radically altered world, where a seemingly distant power was able to dramatically alter the nature of their every day. These shifts introduced an arrhythmia into the hydroscape: ecological, fishing, and religious cycles adapted to a seasonal river were off sync with power demands. The radical alteration that dams make to the landscape, in the promise of irrigation, electrification, and the sheer feat of changing a river, are a tangible symbol of the state's power over its land. But with a deep look into hydropower projects—in this case, the dams across the midstream of the Mekong in Laos and China—the story grows more convoluted. Here are conflicting narratives of power: state-focused, international, and royalist; as well as religious, ecological, and hydrosocial. Here, too, as I found in my eight years of fieldwork in Lao-speaking Thailand, is an alteration in time, where the rhythms of the river change the rhythms of life, and where the cyclical riparian clock clashes with a future-oriented developmentalist notion of time.

Findings of Longfin Baikal Sculpin Cottocomephorus inermis (Yakovlev, 1890) and Baikal Yellowfin C. grewingkii (Dybowski, 1874) in the Downstream Pool of the Boguchanskaya Hydroelectric Power Station

Findings of Longfin Baikal Sculpin Cottocomephorus inermis (Yakovlev, 1890) and Baikal Yellowfin C. grewingkii (Dybowski, 1874) in the Downstream Pool of the Boguchanskaya Hydroelectric Power Station

A Field Test Study on the Instability of a Pump-Turbine under Turbine Mode

Abstract In the context of increasing demand for flexible operation of hydropower plants, this study analyses the factors leading to instability in a prototype pump turbine under turbine mode, based on experimental data collected on-site. Pressure sensors and accelerometers were installed to compare pressure signals and vibration acceleration signals. The test results show that the characteristics of pressure fluctuation are dominated by three specific factors under different output power. Vibration reaches its maximum value at approximately 30% of the rated output and its minimum value at around 70% of the rated output, and the causes of twice increases in vibration is not the same. These characteristics often indicate potential unsteady flow, vortex-induced vibration, and flow separation, subsequently affecting the stability of the pump turbine. Understanding the conditions and severity of the occurrence of instability characteristics in the unit is of great significance for power plant personnel to adjust the unit’s operation strategy and improve operational efficiency.

Research on the Digital Maintenance Construction of Hydropower Unit

Abstract At present, the single unit capacity of hydropower unit is increasing, and the problems of difficulty, high precision, large number of labors and high cost in the maintenance process of large unit are becoming increasingly prominent. With the proposal of intelligent construction of hydropower plant, digital maintenance of hydropower unit has become a research hotspot. This article proposes a construction idea for a digitized maintenance system for hydraulic units based on technologies such as RFID, IoT, and artificial intelligence. This system can modularly manage the unit components and realize the integration and interaction of unit maintenance information through the visualization platform. It utilizes IoT sensors to collect comprehensive information on the components involved in the maintenance process. The components’ information is managed in a hierarchical manner using device KKS coding and a hierarchical structure diagram of the hydraulic unit’s equipment components. Through a visualization platform and equipment knowledge base, the component information is processed and analyzed to generate optimal assembly sequences and paths, thus improving the scientific and rational aspects of the unit’s maintenance process. This approach provides theoretical support for maintenance operations and enhances overall work efficiency.

Investigation on hydraulic characteristics of a model and prototype bulb turbine based on similarity criteria

Abstract From the perspective of the world hydropower utilization trend, the medium and high head hydraulic resources are gradually decreasing, and along with much more attention to the ecological environment and land resource constraints, low-head hydropower plants have been becoming particularly prevalent. Benefit from compact structure, less investment, high capacity and wide operation range, bulb tubular turbines have come up to be the optimal option for the development and exploitation of low-head energy resources and been widely applied. In this paper, based on measurement data and CFD simulation results of model and prototype, scale effect which derived from similarity law was picked up to investigate the hydraulic performance and operating properties. Through comparison and analysis, it’s concluded that distinct from high-head application similarity conversion turns out to be more complicated for bulb turbines in case of flow characteristics, and it’s recommended that this conversion be further modified considering different boundary conditions. Such achievements will be of great help to look into the mechanism of ratio effect and accelerate research progress.

Research on Low Voltage Ride-through Characteristics of 300 MW VSPSH Based on BPA

Abstract With the development of new energy, the power grid scale is constantly expanding, which also brings new challenges to the stability of the grid. When some faults occur in the power grid, it leads to a voltage dip; if most of the devices are removed from the power system, it is easy to cause problems of stability and losses. Therefore, it is necessary to investigate the low voltage ride-through (LVRT) characteristics of power electronic equipment with large capacity before grid connection. Different from constant-speed pumped-storage hydropower plants (CSPSH), variable-speed pumped-storage hydropower (VSPSH) units have broad prospects for development in China due to their characteristics of frequency and voltage regulation, energy saving, and high efficiency. In this paper, the three-machine-nine-node model of 300 MW VSPSH is built based on BPA, and the large voltage dip caused by a three-phase short-circuit fault at the grid side is designed to test the LVRT capability of 300 MW doubly fed VSPSH.

River systems under peaked stress

The change in the global energy production mix towards variable renewable energy sources requires efficient utilization of regulated rivers to optimise hydropower operations meet the needs of a changing energy market. However, the flexible operation of hydropower plants causes non-natural, sub-daily fluctuating flows in the receiving water bodies, often referred to as ‘hydropeaking’. Drastic changes in sub-daily flow regimes undermine attempts to improve river system health. Environmental decision makers, including permitting authorities and river basin managers facing the intense and increasing pressure on river environments, should consider ecosystem services and biodiversity issues more thoroughly. The need for research innovations in hydropeaking operation design to fulfil both the water and energy security responsibilities of hydropower is highlighted. Our paper outlines optimized hydropeaking design as a future research direction to help researchers, managers, and decision-makers prioritize actions that could enable better integration of river science and energy system planning. The goal of this is to find a balanced hydropower operation strategy.

Research on incipient and critical cavitation of a Francis turbine

Abstract Cavitation is an important performance index to evaluate the comprehensive performance of hydraulic turbine. Determination of the plant cavitation coefficient is one of the most important tasks in the design phase of a hydro-power station. In order to improve the design rationality of the cavitation coefficient, numerical simulations of a Francis turbine were carried out to study the cavitation evolution characteristics. A detailed comparative analysis were made to clarify the different cavitation coefficients and impacts on the Francis turbine. Discussions on plant cavitation coefficient selection of hydro-power plant were made form the perspective of cavitation influence on the unit. Based on these investigations, it can be concluded that a certain safety margin of incipient and critical cavitation coefficient were needed considering the rapid efficiency drop near the critical cavitation and serious pressure pulsation near the incipient cavitation condition. The ratio between the plant cavitation coefficient and critical cavitation of the studied Francis turbine were larger than the current standard in China, which means the good cavitation performance of the unit after it put into operation. This study can provide a reference for determining the cavitation coefficient more accurately and ensuring the operation safety of the unit.

Stability analysis of a hydropower plant containing pipe and channel flows

Abstract This work studies the operational stability of the tailrace network containing mixed types of flows in a hydropower station with the complex frequency-domain networked transfer matrix method. First, the networked transfer matrix of the system plant is built based on the dynamic equations of the pipes, channels and hydraulic boundaries in the system. Then, the model is applied to analyze the stable state of the water conveyance network of a hydropower plant located in southwest China. The values of hydraulic state variables at the critical stable point under the multi-machine operating condition are obtained via eigenvalue analysis. The proposed overall transfer matrix model is proved to achieve satisfactory performance by the comparison of the statistic indexes obtained from modeling computation and those from the measured data.

PENGARUH VARIASI TINGGI SUDU TURBIN DARI TINGGI BASIN TERHADAP DAYA DAN EFISIENSI TURBIN VORTEX

Electrical energy is a very important need for human life in various aspects, both on a large and small scale. One of the efforts to reduce the use of fossil fuels is to use natural resources that are not limited and can be renewed. Micro Hydro Power Plant (MHP) is an alternative source of electricity for the community, one of which is a vortex turbine. The vortex turbine is one type of micro hydro turbine that utilizes a whirlpool as a blade drive. This study examines the effect of blade height variations of 25%, 30%, and 35% of the basin height on power and efficiency. The results showed that the largest turbine power at 25% blade height variation from the basin height with a discharge of 0.009 m3/s was 3.294 Watt with an efficiency of 51.10%. The largest turbine power at an angle variation of 30% of the basin height with a discharge of 0.009 m3/s is 3.364 Watt with an efficiency of 50.66%. The largest turbine power at an angle variation of 35% of the basin height with a discharge of 0.009 m3/s is 4.062 Watt with an efficiency of 62.35%. Turbine power based on two-way anova analysis shows that between variations in turbine height and flow discharge have a significant effect on the turbine power produced and turbine efficiency based on two-way anova analysis shows that between variations in turbine height and flow discharge have a significant effect on the turbine efficiency produced.

Assessing Voltage and Frequency Instability in Renah Kemumu's Micro Hydro Power Plant

The increasing demand for energy and the need for environmental sustainability have led to the adoption of renewable energy sources, such as micro-hydropower plants (PLTMH), in isolated communities in Indonesia. However, voltage and frequency instability issues are commonly encountered in PLTMH systems, which undermine their performance. In 2009, a micro-hydropower plant with a capacity of 30 KW was built in Renah Kemumu village. Ranah Kemumu village is located in Jangkat sub-district, Merangin district, Jambi province. In this study, the voltage and frequency instability of PLTMH in Renah Kemumu Village were investigated. The methodology employed in this study was observational. The voltage and frequency data were measured and recorded during peak load hours from 18.00 to 21.00 over one month. The percentage increase relative to the standard voltage and frequency was calculated. Boxplots were generated to visualize the distributions. The voltage measurements showed maximum and minimum values of 270 V and 264 V, representing increases of 22.72 % and 20.45% from the 220 V (standard set by the power utility (PLN)). The frequency ranged from 66.32 Hz to 57.46 Hz, corresponding to 30.92% and 14.92% deviations from the 50 Hz (standard set by the power utility (PLN)). These values exceeded the tolerance limits of the State Electricity Company of Indonesia. The analysis indicates that the voltage and frequency levels at the PLTMH in Renah Kemumu Village are unstable during peak loads, with fluctuations stemming from changing water flows, load currents, and weather conditions

Design of hybrid solar and pyco hydro power plant using water reservoir tank

Design of hybrid solar and pyco hydro power plant using water reservoir tank

ЭНЕРГЕТИЧЕСКИЙ ПЕРЕХОД И ЭНЕРГОСБЕРЕЖЕНИЕ НА НОВОМ ЭТАПЕ РАЗВИТИЯ

The problem of increasing energy efficiency in the Russian Federation is considered. The USSR energy system was unique in size and efficiency; due to large interconnected energy facilities and the development of district heating, it made it possible to efficiently consume fuel, which resulted in annual savings of 40-60 million tons of standard fuel and 10-15 GW of capacity. After a period of decline in the 90s of the last century, over the past 15 years the country's energy consumption has increased by a third, and structural changes have occurred in the main energy-intensive sectors of the Russian economy. It is noted that industry accounts for about 45% of the Russian energy balance, which is many times more than thermal power engineering (21%). The country's reserves for energy saving and energy efficiency can be divided into two groups. System reserves, consisting of an increase in the capacity and load of “carbon-free” sources - hydroelectric power stations and nuclear power plants, active use of losses and heat from technological processes, optimization of heat supply schemes, account for more than two-thirds of the potential for increasing energy efficiency. The second group consists of the use of renewable energy sources, waste, and biofuels. The country’s energy strategy should not consist in the quick payback of energy-saving projects, but in working on the systemic, multiplier effects of industrial development and infrastructure projects, the growth of large and small cities, and the development of hard-to-reach areas.

Comprehensive forecasting of California’s energy consumption: A multi-source and sectoral analysis using ARIMA and ARIMAX models

California’s significant role as the second-largest consumer of energy in the United States underscores the importance of accurate energy consumption predictions. With a thriving industrial sector, a burgeoning population, and ambitious environmental goals, the state’s energy landscape is dynamic and complex. This paper presents a comprehensive analysis of California’s energy consumption trends and provides detailed forecasting models for different energy sources and sectors. The study leverages ARIMA and ARIMAX models, considering both historical consumption data and exogenous variables. We address the unique challenges posed by the COVID-19 pandemic and the limited data for 2022, highlighting the resilience of these models in the face of uncertainty. Our analysis reveals that while fossil fuels continue to dominate California’s energy landscape, renewable energy sources, particularly solar and biomass, are experiencing substantial growth. Hydroelectric power, while sensitive to precipitation, remains a significant contributor to renewable energy consumption. Furthermore, we anticipate ongoing efforts to reduce fossil fuel consumption. The forecasts for energy consumption by sector suggest some decline in the commercial and residential sectors, reflecting California’s recently declining population and the shift away from brick-and-mortar shops and offices to online websites and remote work. In contrast, the industrial and transportation sectors are expected to experience some growth until they return to more constant pre-COVID levels.