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Hydropower, wind power, and photovoltaic power generation are the most common clean energy sources and are important ways to achieve “carbon neutrality” and “carbon peak”. With the adjustment of China’s energy structure, wind power and photovoltaic power generation have entered the peak period of development, but the above two forms of power generation have a certain degree of instability, which has increased the risk of safe and stable operation of the power grid. In contrast, hydroelectric power generation has good stability, and giving full play to the excellent peak and frequency modulation functions of hydro-generator sets is of great significance to ensuring the safe and stable operation of the power grid. This requires the hydro-generator unit to have good reliability during the service period. Through the evaluation of the unit’s health status, the unit’s health status can be predicted, and the maintenance strategy can be given to eliminate the fault in the budding state. This article summarizes the health status assessment methods of hydro-turbine generator sets, and puts forward five health status levels: “healthy”, “good”, “attention”, “abnormal” and “dangerous”. This paper has carried out a quantitative calculation on the health status of a certain hydraulic turbine. The results show that the degree of health of the turbine is “healthy”, “good”, “attention”, “abnormal” and “dangerous” respectively and the degrees are 0.065, 0.632, 0.279, 0.024, 0. According to the principle of maximum membership, it can be judged that the turbine is in “good” status. The evaluation result is consistent with the actual operation of the unit, indicating that the evaluation method studied in this paper has a certain practicability and can provide scientific guidance for the health evaluation of the hydroelectric generating unit.

В ході цього дослідження розробляється та оптимізується програмне забезпечення для аналізу напружено-деформованого стану лопаті низьконапірної поворотно-лопатевої гідротурбіни. Аналізується математична модель, згідно з якою лопать, яка насправді є пологою оболонкою і закріплена частково, замінюється пластиною змінної жорсткості, що представляє в плані кільцевий сектор з затисненим внутрішнім дуговим краєм. В ході дослідження розроблено прикладне програмне забезпечення, яке дозволяє за допомогою варіаційного методу Рітца проводити дослідження напружено-деформованого стану різних лопатей в залежності від їх геометричних і механічних параметрів, а також зовнішніх навантажень. Геометричними параметрами лопаті є: внутрішній і зовнішній радіуси кільцевого сектора, кут кільцевого сектора, максимальна товщина лопаті і інтерполяційна сітка для знаходження відносних товщин лопаті. Механічними параметрами є модуль Юнга і коефіцієнт Пуассона матеріалу, з якого виготовлена лопать, навантаження приймається рівномірно розподіленим. Оскільки товщина лопаті змінна, вхідними даними є відносні товщини лопаті в різних точках. Для обчислення проміжних значень застосовуються білінійна інтерполяція і інтерполяція Лагранжа 9-ї степені. Аналізується точність і обчислювальна складність методів чисельного інтегрування, а саме інтерполяція підінтегральної функції поліномом з подальшим аналітичним обчисленням і використання квадратурної формули, отриманої в результаті повторного інтегрування із застосуванням формули Сімпсона. На підставі порівняння результатів робиться висновок про доцільність застосування поліноміальної інтерполяції з подальшим аналітичним розв’язком. За допомогою розробленого програмного комплексу проводиться розрахунок напружено-деформованого стану пластини, яка апроксимує реальну модель лопаті ЛМЗ (ПЛ510), результати якого порівнюються з експериментальними даними. Здійснюється аналіз декількох конфігурацій лопаті., In this paper, software, that allows studying the stress-strain state of the blade of a low-pressure hydraulic turbine, is being developed. A mathematical model according to which the blade, which is actually a hollow shell and is partially fixed, is replaced by a variable stiffness plate, representing in plan an annular sector with a pinched inner arc edge, is analyzed. In this paper, application software which enables the stress-strain analysis of various blades to be investigated using the Ritz variation method, depending on their geometrical and mechanical parameters as well as external loads, is being developed. The geometrical parameters of the blade are: inner and outer radii of the annular sector, annular sector angle, maximum blade thickness and relative thicknesses at different points. Mechanical parameters are the Young’s modulus and the Poisson's ratio of the material from which the blade is made, and the load is assumed to be evenly distributed. Since the thickness of the blade is variable, the input data is the relative thicknesses of the blade at different points. Bilinear interpolation and Lagrange polynomials of 9th degree are used to calculate the intermediate values. Based on the comparison of the results, the conclusion, that using bilinear interpolation is more expedient for calculating the value of sub-integral function, is made. The accuracy and temporal complexity of the numerical integration methods are analyzed, namely interpolation of the sub-integral function by a polynomial followed by analytical calculation and the use of a quadrature formula resulting from repeated integration using the Simpson’s rule. Based on the comparison of the results, the conclusion, that polynomial interpolation with the subsequent analytical solution is expedient, is made. The developed software package is used to calculate the stress-strain state of the plate that approximates the real LMZ blade (PL510). The results are compared with experimental data. Several blade configurations are also analyzed.

The article shows that an increase in the pressure of the water flow in the hydraulic system after a hydraulic shock (water hammer) can be used to rotate the hydroturbine of a power plant in the same way as when the water pressure is increased in dam hydroelectric plants. The possibilities of using accumulators to stabilize the pressure and flow rate of water after a water hammer are shown. The basic laws of the course of complete and incomplete hydroblow are considered. The advantages of hydraulic shock power plants in comparison with dam hydroelectric power stations and with all other power plants of the same capacity are disclosed. Indisputable advantages include, first of all, the absence of the need for energy consumption from external sources, low costs for design, manufacture and operation. The inertia forces of a constant volume of circulating water are used as a source of renewable energy. The small dimensions of hydroshock power plants make it possible to use them directly in the place of electricity consumption, therefore losses during its transportation are excluded. Water hammer power plants do not affect environmental changes, do not pollute water, air and soil. By regulating the operation of the valves, it is possible to significantly increase the power output of the power plant using modern high-speed solenoid valves or electric valves, which are turned on and off according to a given program. The possibility of using the developed hydraulic shock installation to rotate a bucket hydraulic turbine and generate electricity is being investigated. The widespread introduction of high-impact hydroelectric power plants will permanently get rid of the use of expensive energy sources and keep the human environment clean., В статье показано, что увеличение давления потока воды в гидросистеме после гидравлического удара (гидроудара) можно использовать для вращения гидротурбины электростанции так же, как и при повышении для этого напора воды в плотинных гидроэлектростанциях. Показаны возможности применения гидроаккумуляторов для стабилизации давления и расхода воды после гидроудара. Рассматриваются основные закономерности протекания полного и не полного гидроудара. Раскрыты преимущества гидроударных электростанций по сравнению с плотинными гидроэлектростанциями и со всеми иными электростанциями такой же мощности. К неоспоримым преимуществам относятся прежде всего отсутствие необходимости потребления энергии от внешних источников, низкие затраты на проектирование, изготовление и эксплуатацию. В качестве источника возобновляемой энергии используются силы инерции постоянного объёма циркулирующей воды. Малые габариты гидроударных электростанций позволяют использовать их непосредственно в месте потребления электроэнергии, поэтому исключаются потери при её транспортировке. Гидроударные электростанции не влияют на изменения окружающей среды, не загрязняют воду, воздух и почву. За счет регулирования работы клапанов можно существенно повысить выходную мощность электростанции, используя быстродействующие современные электромагнитные клапаны или клапаны с электроприводом, включение и отключение которых осуществляется по заданной программе. Исследуется возможность использования разработанной гидроударной установки для вращения ковшовой гидротурбины и производства электроэнергии. Широкое внедрение гидроударных электростанций повышенной мощности позволит навсегда избавиться от использования дорогостоящих энергоносителей и сохранить в чистоте среду обитания человека., У статті показано, що збільшення тиску потоку води в гідросистемі після гідравлічного удару (гідроудару) можна використовувати для обертання гідротурбіни електростанції так само, як і при підвищенні для цього напору води в гребельних гідроелектростанціях. Показано можливості застосування гідроакумуляторів для стабілізації тиску і витрати води після гідроудару. Розглядаються основні закономірності перебігу повного і неповного гідроудару. Розкрито переваги гідроударних електростанцій в порівнянні з греблею гідроелектростанції і з усіма іншими електростанціями такої ж потужності. До незаперечних переваг відносяться перш за все відсутність необхідності споживання енергії від зовнішніх джерел, низькі витрати на проектування, виготовлення та експлуатацію. Як джерело відновлюваної енергії використовуються сили інерції постійного об'єму циркулюючої води. Малі габарити гідроударних електростанцій дозволяють використовувати їх безпосередньо в місці споживання електроенергії, тому виключаються втрати при її транспортуванні. Гідроударні електростанції не впливають на зміни навколишнього середовища, не забруднюють воду, повітря і грунт. За рахунок регулювання роботи клапанів можна істотно підвищити вихідну потужність електростанції, використовуючи швидкодіючі сучасні електромагнітні клапани або клапани з електроприводом, вмикання або вимикання яких здійснюється за заданою програмою. Досліджується можливість використання розробленої гідроударної установки для обертання ковшовоъ гідротурбіни і виробництва електроенергії. Широке впровадження гідроударних електростанцій підвищеної потужності дозволить назавжди позбутися від використання дорогих енергоносіїв та зберегти в чистоті середовище проживання людини.

A two-phase hydraulic turbine’s performance and flow field were predicted under different Inlet Gas Volume Fractions (IGVF) with incompressible and compressible models, respectively. The calculation equation of equivalent head, hydraulic efficiency, and flow loss considering the expanding work of compressible gas were deduced based on the energy conservation equations. Then, the incompressible and compressible results, including the output power and flow fields, are compared and analyzed. The compressible gas model’s equivalent head, output power, and flow loss are higher than the incompressible model, but the hydraulic efficiency is lower. As the IGVF increases, the gas gradually diffuses from the blade’s working surface to its suction surface. The gas–liquid separation happens at the runner outlet in the compressible results due to the gas expansion. The area of the low-pressure zone in the incompressible results increases with the IGVF. However, it decreases with the IGVF in the compressible results. As the gas expands in the blade passage, it takes up more flow area, causing the high liquid velocity in the same passage. The runner’s inlet gas distribution affects the liquid flow angle, causing the inlet shock and high TKE areas, especially in the blade passage near the volute tongue. The high TKE area in the compressible results is larger than the incompressible results because the inlet impact loss and the liquid velocity in the blade passage are higher. This paper provides a reference for selecting gas models in the numerical simulation of two-phase hydraulic turbines.

Orientador: Lubienska Cristina Lucas Jaquiê Ribeiro Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia Resumo: Uma das principais tarefas de controle numa Usina Hidrelétrica é a regulação das máquinas hidráulicas. Seu monitoramento faz-se necessário para garantir e estabelecer regras operacionais seguras para a instalação. A turbina é um dos elementos básicos de uma Usina Hidrelétrica e o regulador tipo PID é um dos tipos usados para sua regulação. Os parâmetros do regulador da turbina hidráulica são muito estudados, inclusive verificando seu comportamento através da simulação computacional. As simulações computacionais são ferramentas de análise muito úteis e que permitem encontrar a melhor solução que proporcione o melhor desempenho do sistema estudado. Este trabalho apresenta uma metodologia para otimização das constantes do regulador tipo PID de turbina hidráulica utilizando um modelo de simulação aliado a técnicas atuais de otimização evolutiva baseada nos Algoritmos Genéticos. Os exemplos avaliados mostraram significativa melhora nos valores dessas constantes, mostrando a eficácia do uso dessa ferramenta na área da Hidráulica e possibilitando estudos futuros Abstract: One of the main tasks of control in a Hydroelectric Power Plant is the hydraulic machines regulation. Its monitoring becomes necessary to guarantee and to establish safe operational rules for the installation. The turbine is one of the basic elements of the Hydroelectric Power Plant and the PID governor is one of the types used to its regulation. The governor parameters of the hydaulic turbine are studied, also verifying its behavior through the computational simulation. The computational simulations are very useful analysis tools to find the best solution to provide the best performance of the studied system. This work presents a methodology to optimize the PID governor parameters of the hydraulic turbine using a simulation model ally the current techniques of evolutionary optimization based in the Genetic Algorithms. The evaluated examples had shown significant improvement in the constants values, showing the effectiveness use of this tool in the hydraulic area and making possible future studies Mestrado Tecnologia e Inovação Mestre em Tecnologia

This paper presents the data obtained from the CFD simulation of a pico-hydraulic turbine designed for electric power generation in residential units. Pico-hydro turbine systems are a booming option that seeks to take advantage of small waterfalls and/or streams to generate electricity in a clean way. The data collection process was carried out through simulations developed to a model created in SolidWorks, with the help of the ANSYS CFX software in which the solver configuration was adjusted to the parameters suggested by the manufacturer's manuals (ANSYS) and the boundary conditions were determined based on the current regulatory standards for drinking water systems for Colombia. These boundary conditions influence the operation of the turbine, which is why three runs were carried out corresponding to three points of operation and to obtain the output pressure, the fall of the turbine and the hydraulic power that the device would utilise. The data, acquired in a strict manner, offers potential support for further research in the area and the possible manufacture of prototypes. It also encourages the development of simulations and laboratory tests of this type of device in which geometric factors or operating conditions could be modified.

Воронин Сергей Григорьевич, д-р техн. наук, профессор кафедры «Летательные аппараты», ЮжноУральский государственный университет, г. Челябинск; voroninsg@susu.ru. Давлатов Азамджон Махмадиевич, аспирант кафедры «Летательные аппараты», Южно-Уральский государственный университет, г. Челябинск; davlatov_azam@bk.ru. Султонов Оламафруз Олимович, аспирант кафедры «Летательные аппараты», Южно-Уральский государственный университет, г. Челябинск. Косимов Бахтиёр Исматуллович, аспирант кафедры «Летательные аппараты», Южно-Уральский государственный университет, г. Челябинск. Гулов Диловар Юсупович, аспирант кафедры «Летательные аппараты», Южно-Уральский государственный университет, г. Челябинск. S.G. Voronin, voroninsg@susu.ru, A.M. Davlatov, davlatov_azam@bk.ru, O.O. Sultonov, B.l. Kosimov, D.Yu. Gulov South Ural State University, Chelyabinsk, Russian Federation Представлен краткий анализ существующих малых ГЭС Республики Таджикистан. В результате анализа проблем, усложняющих эксплуатацию мини-ГЭС, отмечены элементы, не позволяющие их использовать в автономном режиме и снижающие надёжность работы. Предлагается для обеспечения надёжной работы мини-ГЭС и возможности эксплуатации в необслуживаемом режиме строить её на основе конструктивно простых и надёжных устройств. При этом появляется возможность отказаться от непрерывного наблюдения за работой мини-ГЭС обслуживающим персоналом и обойтись периодическими регламентными проверками. В качестве турбины предлагается использовать центробежный насос, не нуждающийся в дополнительных операциях управления рабочими режимами, а в качестве генератора - синхронную машину с возбуждением от постоянных магнитов, не требующую наличия канала организации и регулирования потока возбуждения. Качество вырабатываемой энергии предлагается обеспечить с помощью полупроводникового преобразователя напряжения, который должен осуществлять стабилизацию с заданной точностью частот и амплитуд входного напряжения мини-ГЭС. В состав мини- ГЭС предлагается ввести устройства для самодиагностики, осуществляющие контроль не только качества входного напряжения, но и состояние основных элементов мини-ГЭС - турбин, преобразователя напряжений, коммутационной аппаратуры и устройства связи с центральным диспетчерским пунктом. В статье показаны также проблемы, возникающие при реализации предлагаемой структуры, касающиеся в основном обеспечения симметрирования входного напряжения при существенно несимметричной нагрузке, а также повышения достоверности и надёжности устройств диагностики состояния отдельных элементов мини-ГЭС и пути их решения. The article briefly analyzes the existing small hydropower plants in the Republic of Tajikistan. Analysis reveals why such units are not suitable for stand-alone operation and what renders them less reliable. The paper proposes a simpler design for better reliability and stand-alone, low-maintenance operation. A design based on simpler and more reliable components requires less maintenance, which could be limited to regular inspections, hence no need for round-the-clock staff presence. A centrifugal pump is proposed as a turbine, as it does not require additional parameter controls, while a synchronous permanent magnet-excited unit is proposed as a generator, as it does not require a special channer to control the excitation flux. For better quality of generated electricity, the paper proposes using a semiconductor-based voltage converte that will stabilize the input voltage to a required accuracy of frequency and amplitude. Self-diagnosis instrumentation is part of the design, as it can monitor not only the input voltages, but also the condition of primary components: turbines, voltage converters, switches, and communications with the mission control center. The paper also analyzes the problems of implementing this design, which mainly pertain to balancing the input voltage given a significantly asymmetrical load; another challenge is to improve the accuracy and reliability of instrumentations implemented to monitor the health of specific small-HPP elements.

Рассмотрены достоинства и недостатки, пути решения существующих проблем, а также перспективы развития приливных электростанций., The advantages and disadvantages, solutions to existing problems, as well as pro-spects for the development of tidal power plants are considered.

The purpose of the study is development of a structural scheme of mining-engineering system designed to ensure energy performance of the mine water outflow system. The article reveals the need for research aimed at improving the energy efficiency of the water outflow system by comparing the dynamics of electrical energy consumption and commercial output volume at the mining industry enterprises. A brief overview of the global experience in compensation for growth of electric energy consumption under more difficult mining conditions and mining depth due to the use of innovative technological solutions in the mine water outflow system is given. Scientific novelty of the research is the use of energy, which is bypassed to the underlying horizons of the underground mine, of technological and natural waters to improve efficiency of pumping units by using boost pressure and automated processes of cleaning hydraulic flows from sludge deposits, as well as to reduce the overall operational costs in the water outflow system. The energy-efficient scheme of mine water outflow system that increases energy efficiency of a mining enterprise is substantiated.

A mini hydropower Plant is planned to be constructed on an artificial irrigation canal with a maximum flow rate of 40 m3/sec and a water head of 20 m. The canal irrigation schedule lasts for 10 months per year; January and February are usually considered as a period for the maintenance of the hydraulic works. For purpose of comparison, five different designs of HPP and 3 alternatives of installed electric power were proposed and considered in order to choose technically and economically optimal solution. To compare and evaluate alternatives, in this study we take into consideration calculation of total electric energy produced in 2 years. Calculation includes also cost of civil works, cost of mechanical and electrical works, costs of operation and maintenance and cost of investment. As result of this study the best alternative to be installed in mini HPS was chosen.

Studies are conducted on axial hydraulic turbine for very low head application which operates on low speed. Design optimization is generated by optimizing the blade airfoil and blade cascade during development of the turbine blades. Blade airfoil is optimized to obtain optimum value of ratio of Lift coefficient Cl and Drag coefficient Cd, in the range of turbine operation by utilizing of XFOIL that controlled via MATLAB. These airfoils are used to develop the blade cascade. To increase the benefits of fluid flow passing through the turbine blades, the analysis and optimization of the blade cascade is conducted. Vortex panel method is used to analyze the fluid flow inside cascade to gain the maximum of the lift force, in order to optimize the potential power of the fluid that can be utilized by the turbine rotor. The cascade optimization is including arrangement of the incidence angle of the cascade to reduce cascade losses and blade loading by applying the concept of shock-free inflow. Numerical analyses are conducted to determine the performance of the designed turbine with the commercial CFD. The results of numerical simulations show that the turbine can be operated at a maximum efficiency of 91% at various ranges of flow rates.

This work is devoted to the investigation of oscillations in the hydropower plants, consisting of synchronous generator, hydraulic turbine and speed governor. It is motivated by the accident happened on the Sayano-Shushenskaya hydropower plant in 2009 year. A mathematical model of the hydropower unit is based on the equations of Park-Gorev for synchronous generator described in detail in (Adkins, 1962), (Boldea, 2006), on the turbine equations taken from (Pervozvanskii, 1986), and on the simplified equation of governor suggested in (Merkur'ev and Shargin, 2008). For modeling the system parameters of the Sayano-Shushenskaya hydropower plant were used. Oscillations in zones, which were not recommended for operation, were found. The obtained results are consistent with full-scale tests results carried out for hydropower units of the Sayano-Shushenskaya hydropower plant in the late 80s of the XX century and published in (Gluhih, 1988).

In this study, a rotor-bearing-runner system (RBRS) considering multiple nonlinear factors is established, and the complex nonlinear dynamic behavior of the coupling system is studied. The effects of excitation current, radial stiffness, and friction coefficient on dynamic characteristics are analyzed by numerical simulation. The research results show that the dynamic properties of the coupling system caused by different nonlinear factors are interactional. With the changes of different parameters, the RBRS presents multiple motion states, including periodic-n, quasi-periodic, and chaotic motion. The increase of the excitation current Ij has a certain inhibitory effect on the response amplitude of the system and makes the motion state of the system more complex, the chaotic motion wider, and the jump discontinuity enhanced. With the increase of radial stiffness kr, the motion complexity of the coupling system increases, the chaotic region increases, the response amplitude increases, and the vibration intensity increases. With the increase of the friction coefficient &mu, the chaotic region increases first and decreases, the different motions alternate frequently, and the response amplitude gradually increases. This study can not only help to understand the dynamic characteristics of RBRS, but also help the stable operation of the generator set.

During load tripping of the hydraulic turbine at the Bois power plant, the turbined flow is directly transferred and discharged into an external canal without releasing an alert flow. The operation of the turbine in bypass mode, which consists in maintaining flow through the penstock and the turbine nozzles, was therefore envisaged to reduce flow variations in the short-circuited section of the scheme, in which people may be found, particularly during the summer season (safety stake). To validate the feasibility of this type of operating mode and, specifically, to verify the structural integrity in operation of the components impacted by the jet (deflector, control rod, jack…), studies were jointly carried out by EDF and CETIM, and a test-calculation program was initiated. This program included preliminary calculations using a finite element model, a campaign of tests in operating conditions (with vibration measurements and dynamic extensometric measurements) and an analysis of the potential damage due to fatigue. In the end, the study made it possible to show that the damage due to fatigue resulting from the operation of the Bois turbine in bypass operating mode remained in an acceptable range.

The aim of this study was to develop a nano-hydraulic turbine utilizing drop structure in irrigation channels or industrial waterways. This study was focused on an open-type cross-flow turbine without any attached equipment for cost reduction and easy maintenance. In this study, the authors used an artificial indoor waterfall as lab model. Test runner which is a simple structure of 20 circular arc-shaped blades sandwiched by two circular plates was used The optimum inlet blade angle and the relationship between the power performance and the flow rate approaching theoretically and experimentally were investigated. As a result, the optimum inlet blade angle due to the flow rate was changed. Additionally, allocation rate of power output in 1st stage and 2nd stage is changed by the blade inlet angle., Article, INTERNATIONAL JOURNAL OF TURBO & JET-ENGINES. 32(1):65-72 (2015)

Self-fluxed nickel alloys are usually flame fused after thermal spraying. However, due to the practical aspects of high temperatures reached during flame fusing, large structures such as the hydraulic turbines for power generation, can not be efficiently coated. An alternative is to fuse the sprayed coating with a gas tungsten electric arc. In this case, heating is much more intensive and substrate temperature during and after the fusing operation is much lower, thus reducing the possibility that any problem will occur. In this work, coatings of self-fluxed nickel alloy fused by flame and gas tungsten arc were evaluated as protection of hydraulic turbines against cavitational damage. Several tests were performed, including the ASTM ultrasonically vibration-induced cavitation, optical and scanning electronic microscopic metallography, and hardness tests. The results showed that the arc-fused coating presented better cavitation damage resistance, probably due to its finer microstructure. A field application of this new technique is also described. A self-fluxed Ni alloy was flame sprayed in critical regions of Francis-type hydraulic turbine blades and fused by a gas tungsten arc after spraying. The blades will be inspected during the next two years.

We present an accurate fast method for the computation of potential internal axisymmetric flow based on the boundary element technique. We prove that the computed velocity field asymptotically satisfies reasonable boundary conditions at infinity for various types of inlet/exit. Computation of internal axisymmetric potential flow is an essential ingredient in the three-dimensional problem of computation of velocity fields in turbomachines. We include the results of a practical application of the method to the computation of flow in turbomachines of Kaplan and Francis types.

Proyecto Fin de Carrera-Universidad de Salamanca, Escuela Politécnica Superior de Zamora, 2010, [ES]Se presta como punto principal la realización de un diseño de turbina hidráulica, que por las características de salto y caudal impuestas es de tipo Kaplan de doble regulación en montaje vertical. El diseño se enfoca exclusivamente a la hidrodinámica de la turbina y a las partes mecánicas en su interacción., [EN]Is given as a main component of a hydraulic turbine design, which features head and flow rate imposed is double regulated Kaplan vertical mounting. The design focuses exclusively on the hydrodynamics of the turbine and the mechanical parts in their interaction

The aim of this work is to study the primary control system of a hydropower plant in isolated mode. The power plant is modeled by differential equations and results are compared to field data from an actual hydropower plant, presenting deviations lower than 1.0%. The study of primary control system is conducted in order to define useful sets of parameters for controllers. Four controllers are studied: traditional, PI, PID and PI-PD. The performances are evaluated by stability criteria and a performance index. For the hydropower plant studied, the PI controller has the best performance.

A CFD study of hydraulic losses was conducted in order to evaluate present and to propose new solutions of draft tube design at the hydropower plants. Analysis of fluid flow in the HPP outflow structures revealed areas of major contribution to the total losses. Variety of horizontally and vertically placed sheet metal rail vanes were simulated in turbine cone and draft tube elbow region to minimize hydraulic losses and decrease flow vorticity. Fluid flow structures were visually examined and integral quantities of all vane integrated designs were compared against HPP outflow structures without vanes. According to simulation results of various vane designs, guidelines for different construction were recommended and further work proposed.

O presente trabalho pretende contribuir para a melhoria da eficiência dos sistemas de transporte e distribuição de água, possível de conseguir através da recuperação de energia potencial que, em certas situações, existe em excesso em condutas gravíticas. Sendo uma questão já abordada em diversos estudos, as poupanças de energia a que poderá conduzir, justificam a análise de todas as oportunidades, em especial no nosso País, cuja dependência energética do exterior é bem conhecida. Todavia, a implementação de soluções que recorrem à instalação de turbinas em condutas de abastecimento de água, causam naturalmente alguma apreensão às respectivas entidades gestoras, uma vez que pode pôr em causa a integridade das condutas e, em consequência, o abastecimento de água. Neste contexto, o estudo de modelos de controlo específicos para os referidos equipamentos poderá ser um contributo para a implementação mais alargada das soluções de melhoria da eficiência de sistemas de abastecimento de água, através da instalação de geradores hidroeléctricos, que terão a dupla função de controlo de caudal e produção de energia. O estudo e simulação dos modelos de controlo contidos neste trabalho permite concluir que é possível garantir a segurança das condutas e produzir energia eléctrica com turbinas nelas instaladas. Interessa assim aprofundar este tipo de estudos de forma a conseguir modelos de controlo que, com as premissas indicadas, possibilitem a optimização da produção de energia.

Low frequency fluctuations often occur in hydraulic installations equipped with fixed bladed turbines or pumps operating under off design conditions. Passive measures, such as air ad- mission or minor design modifications, are commonly taken as a last resort to try to reduce these phenomena. This article describes an active control approach to the problem, which is based upon a rotating valve exciter. The idea is to create an external excitation with the hydraulic exciter to diminish an undesired frequency component of the turbine’s natural excitation. One of the key elements required for this type of actuator is an adequate control strategy. It is based on a self-tuning extremum control technique, which implements an on-line identification of the optimal system parameters. The operation principles and performance issues are described and illustrated with experimental results obtained on a 90 kW Francis turbine model. The results demonstrate that the pressure fluctuations at a chosen frequency component can efficiently be reduced.

Reverse engineering is an important method utilized in manufacturing and design process. When there is no technical data of a product or it is unusable, the CAD model is obtained with this method. After obtaining the data of the existing product, rehabilitation studies are carried out for improvement in the design. In this rehabilitation process, numerical methods can be used to optimize the current product. This study presents a reverse engineering process of detecting the reasons for lack of performance of an actual hydraulic turbine runner. Reverse engineering methodology is applied for Kahta H.E.P.P. in Turkey, Adiyaman which has two identical horizontal Francis type turbines. The head and discharge are 125 m and 3.25 m(3)/s per turbine, the power plant capacity is 3.66 MW and overall turbine efficiency is 92%. According to the results of this study, it is determined that the turbine runner blade trailing edge theta angle causes a large recirculation region which drops the performance of the turbine.