A reliability, availability and maintainability (RAM) model for electromechanical components in hydropower plants

Integrated framework to optimize RAM and cost decisions in a process plant

A new fuzzy methodology-based structured framework for RAM and risk analysis

Quantitative assessment of risk matrix through analysis of reliability, availability and maintainability (RAM) is used as quick visual tool for managing potential risk in any continuous production system which can be used for further improved maintenance planning. Fault tree analysis along with failure mode and effect analysis support in assessing risk of minor or major failures associated with different consequences of human impact, production loss, maintenance loss etc. For developing risk matrix, scoring of likelihood and severity are necessary to identify the potential risk zone. An attempt has been made in the present study to assess overall failure scenario of offset-printing machine by analysing reliability of different machine component. Different types of failure frequencies and corresponding failure probability of the machine are set as a value representative likelihood failure data. The critical consequences of these failures are discussed for estimation of actual risk and risk index. Matrix of risk and risk priority number is developed here on the basis of likelihood scores of each kind of failure probability and severity scores by considering different types of breakdown and their associated responsible machine component. Moreover, prioritization of different failure types is validated by MonteCarlo simulation. Based on the risk matrix developed, maintainability and maintenance interval time has been determined which seems to be a novel approach for reduction of risk and breakdown time. Finally, maintenance and safety recommendation on the basis of corresponding risk level and maintainability indicator rating are discussed.

This study determines the prone components and the mean time to failure of KMP. Bontoharu. The method used in this research is the qualitative analysis, which comprises the failure mode, effect, analysis (FMECA), fault tree analysis (FTA), and quantitative analysis using Weibull distribution to determine the mean time to failure (MTTF) value. The risk method based inspection and maintenance is used to determine the value of equipment risk and maintenance scheduling model, and the inspection method used is visual check. The results revealed that the value of MTTF filter was 194 hours, separator was 502 hours, and pipe was 2508 hours. Filters and separators have the highest level of risk, while the mainframe, daily trays, transfer pumps, feed pumps, injection pumps, and injector service tanks have medium risk levels. Keywords: fuel system, Reliability, FMECA, FTA, Maintenance

Cogeneration of green hydrogen in a cascade hydropower plant

Every country takes care of energy independence and security by using different energy sources and remarkably increasing electricity production by renewable energy sources. Ukraine is not an exception, especially when the energy infrastructure is significantly damaged during the war and there is a lack of capacities in the energy system. Because of this, the Government of Ukraine is planning a number of measures to launch systems of domestic mini-power plants.Ukraine has favourable conditions for developing the network of small-scale hydropower plants. While the hydropower potential of the largest Ukrainian rivers is used, the potential of small rivers is used only partially. The small-scale hydropower plants were built during the last century very actively. In 1912 the first small-scale hydropower plant was built. From 1923 to 1960, there were 956 hydropower plants with different capacities from a few kW to a few MW. However, at the end of the 1980s, the interest in small hydro decreased because of the construction of the large hydropower plants in the river Dniester and Dnipro, heat and nuclear power plants. Only 49 plants were in operation. Since 1995 the interest in small hydro has increased again. Nowadays, there are about 150 hydropower plants in operation.The paper examines the past and present state of small hydropower plants and perspectives on their development in the future, both by building new or reconstructing existing power plants. The list of hydropower plants with a short description of possible reconstruction is given. Moreover, the way of reducing the negative influence of hydropower plants on the environment is studied. Taking into account the energy issues in Ukraine, the possibilities of off-grid operation of hydropower plants are considered.The importance of energy security was evident from the issues that Ukraine is recently facing. Building new and reconstructing old small-scale hydropower plants will help to ensure the energy security of other types of electricity generation.

This paper describes research into the applicability and value of architecture modeling techniques in conducting failure analysis on a system that is currently in service. Many Systems of Systems (SoS) currently in service did not include architecture modeling in their design and integration phases. In the absence of architectural models, knowledge of critical items, interfaces, and interactions, is difficult to learn, communicate, and maintain. Failure analysis, particularly for SoS, requires comprehensive system knowledge to produce accurate and timely results. This paper contributes specifically by summarizing existing model-based failure analysis research in terms of applicability to in-service systems and by focusing on Fault Tree Analysis (FTA) and Failure Modes Effects Analysis (FMEA). Much of the existing research in this area is either specific to design or development phases of system lifecycle, or presupposes that architectural models exist, and does not approach the topic from the perspective of value and practicality to an in-service system. Firstly, a general analysis of the commonality of principles, methods, and resources used for failure analysis with those of system architecture modeling is presented. The second contribution is a review of system and SoS modeling techniques and current research as applied to these failure analysis methods. The paper concludes with a summary of model applicability to FTA and FMEA, and a brief analysis of the studied methods, which will guide future research and evaluation of architecture modeling-based methods for failure analysis.

While hydropower in California is one the main sources of renewable energy, population growth has continuously increased demand for energy. In addition, recent droughts reduced the amount of available water behind the hydropower dams to provide the water head needed to run the turbines in hydropower plants. A more sustainable alternative, instead of developing new infrastructure, is to enhance the daily operation of reservoirs to support hydropower generation. This study suggests a new optimal operation policy for Folsom Reservoir in California and hydropower plants, which maximizes hydropower generation and reduces flood risk. This study demonstrates the application of the cellular automata (CeA) approach to optimize the daily hydropower operation of Folsom Reservoir. The reservoir operation is a nonlinear problem, where the hydropower generation and elevation-area-storage functions are the main nonlinearity to accurately represent the daily operation of the system. Moreover, the performance of the CeA approach under two extreme climate conditions, wet and dry, was evaluated and compared to the operation during normal conditions. Results showed that the CeA approach provides more efficient solutions in comparison to the commonly used evolutionary optimization algorithms. For the size of the non-linear optimization problem designed in this study, CeA outperformed genetic algorithm for finding optimal solutions for different climate conditions. Results of CeA showed that although the annual average inflow to the reservoir during the dry period was about 30% less than the normal condition, CeA offered about a 20% reduction in average hydropower generation. The new operation policy offered by CeA can partly compensate for the loss of the snowpack in California’s Sierra Nevada under a warming climate. The approach and its outcomes support an informed decision-making process and provide practical reservoir operational guideline to remediate the adverse effects of hydroclimatic changes in the future.

In this era of energy crisis, renewable energy is the most promising solution to man's ever increasing energy needs. But the power production by these resources cannot be controlled unlike in thermal plants. As a result, standalone operation of renewable energy is not reliable. Hence grid-connection of these along with conventional plants is preferred due to the improved performance in response to dynamic load. It is observed that fluctuations in frequency caused due to load variations are high with increase in penetration of renewable resources. In this paper, load frequency control (LFC) for a power system involving wind, hydro and thermal plants is proposed in order to suppress frequency deviations owing to load and generating power fluctuations caused by penetration of renewable resources. A system involving four thermal plants, a wind farm and a hydro plant is modeled using MATLAB R2010a.

Electric energy, which is needed in all areas of life, plays an important role in raising the development level of the society. The demand for renewable energy sources has increased due to the continuous increase in energy need and the exhaustion of non-renewable energy sources. Micro-grids, which emerged as a solution to energy cuts and infrastructure problems in rural areas and areas far from the grid, are small energy grids that can operate independently or independently from the grid. In this study, micro-grids and the advantages of micro-grids, together with the energy production provided by micro-grids, are examined. Being a new energy source and being able to work independently from the grid is the most important feature of the micro grid. Therefore, the working principle of micro hydroelectric power generation systems and wind energy systems and the advantages of the micro grid are indicated by giving examples on their different aspects from other systems. In the MATLAB/SIMULINK program, a wind and micro hydro-electric hybrid power generation system model was designed and the simulation results were specified.

PT. Candi Loka Jamus switched to using micro hydro power plants to meet its electrical energy needs because of the high operational costs and environmental impact of fuel oil power plants. However, during the dry season, the micro hydro power plant is unable to produce enough energy to meet the needs, which could lead to damage of its components and decreased performance. To address this issue, the energy potential of the micro hydro power plant was calculated using operational time simulation and season time simulation. The rain data was analysed using the double mass curve analysis method and arithmetic mean method to calculate the discharge throughout the year. The dependable discharge was calculated using the F.J. Mock method and the basic year method, and the physical potential formula was used to calculate the energy potential. Based on the calculations, the dependable discharge energy potentials of Q80, Q70, Q50, and Q30 were found to be 569,173.91 KWh, 614,737.01 KWh, 589,640.81 KWh, and 619,855.44 KWh, respectively. The efficient operating time of the micro hydro power plant was determined based on the Q80 dependable discharge energy potential with a simulation of operational time. The plant should be active from January 1 to August 15, deactivated for maintenance purposes from August 16 to October 31, and reactivated from November 1 to December 31. With an active period of 287 days, the Jamus micro hydro power plant has an energy potential of 488,732.17 KWh in one year.

One of hydro power plant operational problem is how to maximize available water resouces to gather optimal electric power generation. Water availability which is limited and can be stored in a reservoir will influence electrical energy generated by the plant. This paper present a new approach of short term optimization of hydro power plant operation. The objective function is to maximize energy which is produced by power plant on scheduling operation period, with consider water resource availability in reservoir as operational constraint. The optimization problem is formulated in Linear Programming Method, in which this method is a commonly used to solve optimization problem in hydro power plant. Based on simulation results on Ketenger Hydro Power Plant using water flow data on June 1st 2013 shows that this method can be used to solve hydro power plant operation optimization problem well. Electrical energy as main objective function is maximized and all prevailing constrain is satisfied. On this short term operation (24 hour) simulation, total energy can be produced is 96121,55 kWh, or 1427 kWh (1,51%) greater comparing with real generation condition with 96694 kWh.

The paper presents an overview of development of renewable energy sources (RES) both in Russia and other world economies. It is shown that Russia substantially lags behind in use of RES with the exception of energy from large hydro plants. The reasons are both its abundance with traditional energy sources and insufficient support from institutional and infrastructural environments. Forecasts of future development of RES suggest that despite of possible strong progress the future importance of RES in Russia could hardly reach the levels being achieved in many other economies. Authors own model calculations confirm that programs of RES development in Russia demand for substantial support from the Government.

Resolving the trade-off between silver eel escapement and hydropower generation with simple decision rules for turbine shutdown

Chapter 24 - Recent Updates on Medical Device Safety and Risk Management