The thesis describes the development of a generic nonlinear computer model of a pumped storage hydroelectric scheme. The model combines the hydraulic, electrical and control systems. In particular, this model includes the water hammer effects, the hydraulic coupling in the common water supply tunnel, the power system stiffness and the electrical coupling between the generator and the power system. The benefit of the simulation is that it gives insight into the plant characteristics and improves understanding of the physical phenomena involved. A specific case of the model for Dinorwig power station is tested against the plant responses and establishes a good degree of confidence in the simulation. The model is used to evaluate governor performance and establish stability boundaries for various operating conditions. The model is also used to design a new black-start regime which allows Dinorwig to energise the power system after blackout, with individual units picking up incremental loads up to 15% of machine rating while ensuring that frequency deviations remains within limits. Another application of the model is to explain why a period of sustained power oscillation occurred at Dinorwig and to identify under what circumstances this can take place. Linearised system models are used for governor tuning and root locus and Bode plot methods applied to establish the optimum governor settings for different operation conditions. The results demonstrate the significance of hydraulic coupling and the power system (grid) size on governor tuning. The final part of the work addresses conversion of the model to run in real-time and interfacing it with an actual unit governor. The results demonstrate the practicality of the hardware-in-the-loop simulation as a technique for safely implementing and testing new controllers or enhancements to the current controller.

The aim of this master thesis is to explain using of the pressure-time method, commonly known as Gibson’s method for non-stationary discharge evaluation through water machineries. The thesis included the principle of this method, deriving the method and the problems, which happened in thanks of using this method. In the second part of this thesis are in details shown results of non-stationary discharge by pressure-time method and also there is the computation of the kinetic member on the resulting discharge. Next part is about refinement of this method by evaluation Penstock factor for each segment of feeder (direct pipe, taper and pipe elbow) using MS Excel and CFD calculations. The last capture is about influence of unsteady friction. In the beginning are shown basic terms and explain the principle of this losses. In the next part is proposed numerical model of losses and their influence on calculation of total Penstock factor of feeder.

ENGLISH ABSTRACT: This document details the design process of a 97 kW microhydro system for Roman Bay Sea Farm in Gansbaai in the Western Cape Province of South Africa. It contains a literature study of microhydro power, with a focus on the use of Pump-as-Turbine technology and direct-drive systems. The literature study leads to several possible concepts for the project, which are then evaluated and the most suitable design is found to be a reverse running pump that powers a different pump through a direct drive system. Experimental data from KSB is used to test the accuracy of various correlations that can be used to generate turbine-mode operation curves from pump curves. The final design parameters for the complete system are then determined, and presented along with a cost benefit analysis. / AFRIKAANSE OPSOMMING: Hierdie verslag dokumenteer die ontwerpsproses van ‘n 97 kW mikro hidro stelsel vir Roman Bay Sea Farm in Gansbaai in die Wes-Kaap van Suid Afrika. Dit bevat ‘n literatuurstudie van mikro hidrokrag, met ‘n fokus op Pomp-as-Turbine en direk-gekoppelde stelsels. Die literatuurstudie lei tot ‘n aantal moontlike konsepte vir die projek wat dan evalueer word sodat die mees gepaste ontwerp gekies kan word. Dit word gevind dat ‘n pomp wat verkeerd om hardloop en ‘n ander pomp direk van krag voorsien die mees gepaste ontwerp is. Eksperimentele data van KSB word gebruik om die akkuraatheid van verskeie korrelasies te toets wat gebruik kan word om turbine-mode gedrag van pomp kurwes te bepaal. Die finale parameters van die hele stelsel word dan bepaal en word dan saam met ‘n koste-analise aangebied. / Centre for Renewable and Sustainable Energy Studies

Novige develops a wave energy converter (WEC) concept that utilizes wind-generated wave to create electricity. The system uses a float and a hydraulic cylinder to pump water up to a turbine, similar to an inverted hydro power plant. The penstock system that delivers the fluid to the turbine was optimized for efficiency and a theoretical efficiency of the penstock was calculated. The penstock and the surrounding components were updated to a commercial size. The longer cylinder resulted in a larger loss from the hydrostatic pressure. The optimal pipe diameter was calculated by comparing the friction loss and the additional weight resulting from a larger pipe. For the penstock the piping elements were compared and chosen for a higher efficiency. The penstock system can be optimized for efficiency by using pipe elements with lower coefficients of loss. It is more efficient to divert the flow as little as possible, while maintaining the same flow velocity throughout the system. Losses can be reduced by choosing the optimalpipe diameter size, therefore making the penstock as light as possible, while also reducing thepipe friction. The hydrostatic pressure from the height of the cylinder is the largest source of lossin the system. The efficiency of the redesigned penstock was found to be 93.7%. / Novige utvecklar ett vågkraftverks koncept som utnyttjar vindvågor för att generera elektricitet. Systemet använder sig av en flotte och en hydraulisk cylinder för att pumpa vatten upp till en turbin, det kan liknas vid ett inverterat vattenkraftverk. Tilloppstuben som leder vattnet till turbinen optimerades för effektivitet och den teoretiska effektiviteten av tilloppstuben beräknades. Tilloppstuben och de omgivande komponenterna uppdaterades för den kommersiella varianten. Den längre cylindern resulterade i större förluster på grund av det hydrostatiska trycket. Den optimala rör diametern beräknades genom att jämföra friktions förlusterna och de förluster som uppstår på grund av större rör vikt. Olika rörelementen i tilloppstuben jämfördes och valdes med avsikt på effektivitet. Effektiviteten i tilloppstuben kan optimeras genom att välja rörelement med lägre förlustfaktor. Det är mer effektivt att dela på flödet så lite som möjligt och behålla samma flödeshastighet genom hela systemet. Förlusterna kan minskas genom att välja den optimala rördiametern, vilket ger en så låg vikt som möjligt samtidigt som friktionsförlusterna i röret reduceras. Det hydrostatiska trycket från höjden av cylindern är den största orsaken till förlust i systemet. Effektiviteten av det nya tilloppstubs systemet är 93.7%.

This master’s thesis deals with the feasibility study of the pumped-storage hydropower plant. Design is divided at three parts – upper water-reservoir with water intake, penstock with cabel tunnel and mechanical room with four Francis reversible turbine. Study contains engineering report, hydraulic calculations, photodocumentation and drawing documentation.

O planejamento da fabricação de peças de caldeiraria para hidrelétricas tais como caixa espiral, tubo de sucção e conduto forçado, necessita de bons conhecimentos em caldeiraria e muita experiência na área devido à complexidade dos cálculos, tornando-se uma tarefa trabalhosa e com muitas possibilidades de erros. A seqüência de operações, no entanto, é altamente repetitiva facilitando o desenvolvimento de um sistema computacional de apoio. O trabalho proposto a seguir tem como objetivo apresentar um sistema desenvolvido como um aplicativo em software CAD para auxiliar as tarefas de projetar e fabricar caixa espiral, tubo de sucção e conduto forçado. O sistema colocou o conhecimento técnico da engenharia industrial de hidrogeradores de uma empresa de bens de capital ao alcance de projetistas desta área, de forma a aumentar a produtividade nestas, e em outras atividades similares, minimizando as possibilidades de erro e padronizando os procedimentos de cálculos. Os resultados foram, entre outros, diminuição do tempo de geração das informações para o processo de fabricação, tais como croquis de delineamento e desenhos de montagem, acima de 90% e perda zero de peças na fabricação. / The manufacturing process of hydroelectric weld parts, such as spiral cases, draft tubes and penstocks, demands good knowledge and experience in the area due to the calculations needed, revealing to be a difficult work with a high risk of errors. However, the operation sequence is highly repetitive which enables the development of a computational support system. This thesis has the purpose to present a system developed as an application in CAD software to aid the projecting and manufacturing activities of the spiral boxes, draft tubes and penstocks. Such system was disposed to the technical body of an industrial engineering department maintained by a heavy equipment company which manufactures hydro generators, so professionals were able to increase their productivity, being the system also used in similar areas, minimizing possibilities of mistakes and standardizing calculations procedures. Results were, among others, decrease of time needed to develop process information, such as sketch outlines and assembly drawings, above 90% and zero losses on parts production.

O planejamento da fabricação de peças de caldeiraria para hidrelétricas tais como caixa espiral, tubo de sucção e conduto forçado, necessita de bons conhecimentos em caldeiraria e muita experiência na área devido à complexidade dos cálculos, tornando-se uma tarefa trabalhosa e com muitas possibilidades de erros. A seqüência de operações, no entanto, é altamente repetitiva facilitando o desenvolvimento de um sistema computacional de apoio. O trabalho proposto a seguir tem como objetivo apresentar um sistema desenvolvido como um aplicativo em software CAD para auxiliar as tarefas de projetar e fabricar caixa espiral, tubo de sucção e conduto forçado. O sistema colocou o conhecimento técnico da engenharia industrial de hidrogeradores de uma empresa de bens de capital ao alcance de projetistas desta área, de forma a aumentar a produtividade nestas, e em outras atividades similares, minimizando as possibilidades de erro e padronizando os procedimentos de cálculos. Os resultados foram, entre outros, diminuição do tempo de geração das informações para o processo de fabricação, tais como croquis de delineamento e desenhos de montagem, acima de 90% e perda zero de peças na fabricação. / The manufacturing process of hydroelectric weld parts, such as spiral cases, draft tubes and penstocks, demands good knowledge and experience in the area due to the calculations needed, revealing to be a difficult work with a high risk of errors. However, the operation sequence is highly repetitive which enables the development of a computational support system. This thesis has the purpose to present a system developed as an application in CAD software to aid the projecting and manufacturing activities of the spiral boxes, draft tubes and penstocks. Such system was disposed to the technical body of an industrial engineering department maintained by a heavy equipment company which manufactures hydro generators, so professionals were able to increase their productivity, being the system also used in similar areas, minimizing possibilities of mistakes and standardizing calculations procedures. Results were, among others, decrease of time needed to develop process information, such as sketch outlines and assembly drawings, above 90% and zero losses on parts production.

Den svenska vattenkraften står för nästan 50 % av landets elproduktion vilket gör dess konstruktioner till en viktig del av samhällets infrastruktur. För att ett vattenkraftverk ska fungera effektivt och säkert ställs höga krav på komponenternas funktion och kondition. I dagsläget genomförs därför rutinmässiga kontroller på, i och runt dessa anläggningar. För de aggregatnära inre vattenvägarna genomförs detta ca vart åttonde år i samband med reparationer av turbinerna, vilka då måste tömmas på vatten. För till- och utloppstunnlarna, som ofta är drivna i berg, finns det dock inte några sådana rutiner. Detta i kombination med att majoriteten av Sveriges vattenkraftverk har uppnått en ålder på över 50 år gör att branschen har börjat bli intresserade av att få kännedom om skicket på tunnlarna. Att genom-föra inspektioner genom att torrlägga dessa är dock en tidsödande process som kräver att kraftverket är avstängt under en lång tid och därmed ger en stor ekonomisk förlust för ägaren. Detta arbete har därför utförts med syfte att utvärdera till vilken grad inspektioner med undervattensfarkoster, ROV, kan användas som alternativ till inspektioner av inre vatten-vägar, både aggregatnära och i till- och utloppstunnlarna. En litteraturstudie har genomförts, om vattenkraftverk, vanliga skador, dagens inspektionsmetoder samt hur en ROV är uppbyggd och fungerar. Arbetet innefattar även tre praktiska moment bestående av deltagande på en inspektion av torrlagda aggregatnära inre vattenvägar och en inspektion med ROV i en 2,5 km lång utloppstunnel samt egna försök med inhyrd ROV för att undersöka vilka typer av betongskador som är möjliga att detektera. Resultatet från samtliga delar i arbetet pekar på att besiktningar med ROV kan övervägas för flera olika typer av inspektioner. För till- och utloppstunnlar är denna typ av inspektion många gånger den enda rimliga. För de aggregatnära inre vattenvägarna ger dagens inspektionsmetoder med torrläggning ett fullgott resultat, men ROV skulle kunna vara ett alternativ vid svårtillgängliga delar, t.ex. på grund av utformning eller stora läckage. / Swedish hydro power accounts for nearly 50 % of the country's electricity production which makes the constructions within this production system an important part of the societal infrastructure. To ensure safe and efficient operation of these hydroelectric power plants high demands are put on the components function and condition. Therefore, routine inspections are carried out inside and around these facilities. For the waterways directly connected to the power station, such as penstocks, wicket gates and draft tubes, these checkups are made about every eight years simultaneously as planned repairs of the turbine, when the waterways have to be emptied. For the head and trail race tunnels, which often are driven in bedrock, there are no such routines. This, in combination with the fact that the majority of the Swedish hydroelectric plants have attained the age of over 50 years, has led to an increased interest within the industry in ways to increase their knowledge about the condition of these water passageways. To conduct inspections by draining the tunnels is however a very time consuming process that requires the power plant to be turned off for a long time causing a major financial loss for the owner. The purpose of this master thesis is to assess the extent to which inspections with remotely operated vehicles, ROV, can be used as an alternative method for inspections of covered waterways, both those close to the power house and the head and tail race tunnels. A literature study of hydro power plants, common damages, current inspection methods and the construction and function of an ROV, has been conducted. The method also includes three practical activities, participation at inspections in drained waterways and at an ROV inspection of a 2.5 km tail race tunnel. Furthermore, tests with a rented ROV were carried out to investigate what type of concrete damages that are possible to detect using this method. The result from all parts in this thesis indicates that examinations by ROV can be considered for several types of inspections. For head and tail race tunnels, this type of inspection is often the only reasonable method. For the waterways directly connected to the power station, current inspection methods by draining show good result. But the ROV could here be an alternative in inaccessible areas, for instance due to waterway design or heavy leakage for instance.