Littérature scientifique sur le sujet « Maximum value generator »
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Articles de revues sur le sujet "Maximum value generator"
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Rusilawati, Rusilawati, Irrine Budi Sulistiawati et Naoto Yorino. « Determination of Generator Capability Curve using Modified-Single Machine to Infinite Bus (M-SMIB) System Approach ». E3S Web of Conferences 188 (2020) : 00022. http://dx.doi.org/10.1051/e3sconf/202018800022.
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The capability curve for each generator unit is usually provided by the generator manufacturer. But in practice, the generator can reach its maximum generation limit before reaching the maximum limit on the generator capability curve provided by the generator manufacturer. This might occur because of the load location is far from the generator or the varying of the loading value so that the maximum generation limit is smaller than the value given on the generator capability curve of the manufacturer. In this paper, the generator capability curve is determined using the Modified Single Machine to Infinite Bus (M-SMIB) system approach to determine the maximum generation limit every time there is a change in loading or change in the load location. After the maximum generation limit of each unit generator is known, the generator capability curve that is always in accordance with the real time situation can be formed. Thus, the operation limit of each generator can be recognized, determine the appropriate protection system setting and can prevent the electric power system disturbance. This method will be applied to generator units in the four bus IEEE system with two generators.
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Demeianto, Bobby, Riki Peri Ramadani, Iskandar Musa et Yuniar Endri Priharanto. « ANALISA PEMBEBANAN PADA GENERATOR LISTRIK KAPAL PENANGKAP IKAN STUDI KASUS PADA KM. MARADONA ». Aurelia Journal 2, no 1 (27 novembre 2020) : 63. http://dx.doi.org/10.15578/aj.v2i1.9425.
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Efficiency value is a measure that can inform us that a machine that operates can be said to be efficient or not. This study aims to find the efficiency value of the electric generator on the fishing vessel KM. Maradona. In addition, this study also aims to find the average percentage value of electric current on each phase of the generator and also to find the average value of the percentage imbalance of load sharing in three-phase electrical installations in KM. Maradona. From the calculation, it is found that the percentage of imbalance of three-phase electrical installations KM. Maradona when the generator operates can reach 31.11%. From the calculation, it is also found that the average percentage load on the electric generator of KM. Maradona maximum value is 22.35% with an average current value of 25.50 Ampere. Directly proportional to the maximum average current value, the maximum electrical power value of KM. Maradona is only at 16.80 kVA with an efficiency value of 22.40%.
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Toriki, Mohammad Berel, Muhammad Khamim Asy’ari et Ali Musyafa’. « Enhanced Performance of PMSG in WECS Using MPPT - Fuzzy Sliding Mode Control ». Journal Européen des Systèmes Automatisés 54, no 1 (28 février 2021) : 85–96. http://dx.doi.org/10.18280/jesa.540110.
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The wind turbine is a tool used to convert wind energy into electrical energy. This research applies the maximum power point tracking (MPPT) algorithm combined with the fuzzy sliding mode control (FSMC) to produce maximum power in the wind turbine. Addition of fuzzy logic algorithm to sliding mode control to reduce the chattering phenomenon caused by the high switching frequency of the MOSFET in the boost converter. The permanent magnet synchronous generator (PMSG) type of generator with a capacity of 600 watts is used to convert the mechanical energy of the turbine into electrical energy. Tracing the maximum power value of the generator with the MPPT-FSMC algorithm in this study based on the value of the generator output voltage, generator output current, and converter output voltage obtained through simulations on MATLAB / SIMULINK. Comparison of wind turbine performance using MPPT-FSMC and without MPPT is shown as validation of improved wind turbine performance when using intelligent control algorithm.
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Rusilawati, Irrine Budi Sulistiawati, Adi Soeprijanto et Rony Seto Wibowo. « Determination of Generator Steady State Stability Limit for Multimachine System based on Network Losses Concept ». MATEC Web of Conferences 164 (2018) : 01041. http://dx.doi.org/10.1051/matecconf/201816401041.
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In the multimachine circumstances, it is difficult to analyze the steady state stability of each generator. In previous research, analysis of the steady state stability limit has been carried out but only look at the stability of the overall system. Therefore, to analyze the stability of each generator, the multimachine system must be changed into a Single Machine to Infinite Bus (SMIB) system by collecting all the loads into one central load in the infinite bus. The method to change from the multimachine system to SMIB system is presented in this paper. The multimachine system is converted into an equivalent impedance (req and xeq) and an equivalent load based on losses concept. After req and xeq is calculated, then by using steady state stability limit concept, the value of the maximum generation of each generator units can be determined. By means of maximum generation is the maximum output power limit that can be generated without causing unstability. ETAP simulation is used to validate the calculation results of the proposed method. The method was applied to units generator in Java Bali system 500 kV.
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Fujieda, Shun, Naoki Gorai, Toru Kawamata, Rayko Simura, Tsuguo Fukuda et Shigeru Suzuki. « Performance of Vibration Power Generators Using Single Crystal and Polycrystal Magnetic Cores of Fe–Ga Alloys ». Materials Science Forum 1016 (janvier 2021) : 453–57. http://dx.doi.org/10.4028/www.scientific.net/msf.1016.453.
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The performance of a vibration power generator using a single crystal core of Fe–Ga alloy was compared with that of a generator using a Fe–Ga alloy polycrystal core with a similar Ga concentration. When the generator using the polycrystal core was forcibly vibrated by 1-G acceleration, the vibration frequency dependence of the open-circuit voltage showed a peak with a maximum value of about 0.14 V at the first resonance frequency due to the inverse magnetostrictive effect. On the other hand, the generator using a single crystal core with a <100> direction parallel to the external stress direction exhibited a maximum value of about 0.26 V, about two-times larger than that of the device using the polycrystal core. Consequently, a vibration energy generator using a single crystal core of Fe–Ga alloy has advantages in performance over a generator using a polycrystal core.
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Gromov, Victor, Vladimir Kuznetsov, Sergey Konovalov, Goui Tang, Gou Lin Song, Kseniya Alsaraeva et Alexander Semin. « Estimation of Current Amplitude Pulse ». Advanced Materials Research 1013 (octobre 2014) : 166–69. http://dx.doi.org/10.4028/www.scientific.net/amr.1013.166.
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Method of estimation of current amplitude (~10 kA) pulses constructed by powerful current pulse generator is suggested. It bases on the solution of differential equation current and voltage change on capacitor. The final formula consists of maximum value of capacitor charge, maximum negative voltage value, pulse duration and capacitor value.
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Cheng, Ruo Fa, et Li Hu Chen. « Maximum Wind Power Tracking Control Based on PID and Feedback Linearization ». Advanced Materials Research 1055 (novembre 2014) : 358–62. http://dx.doi.org/10.4028/www.scientific.net/amr.1055.358.
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Based on the mathematical model of permanent magnet synchronous generator, the paper discussed the effect of the simplifying torque coefficient equation on direct-drive permanent magnet synchronous wind power generator. On the basis of feedback linearization principle, designed a PID and feedback linearization compound controller in this paper, and validated under varying wind speed, power coefficient remains at a constant value, which reached the maximum wind power capture purposes. Using MATLAB/simulink tool to build direct-drive permanent magnet synchronous wind power system simulation model, the paper verify the stability of the system when the external applied load mutate. The result shows that the control strategy of the composite is effective and timely when tacking the maximum power.
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Gavpisarn, Apisak, Suwit Jugsujinda et Tosawat Seetawan. « Thermoelectric Generator of Ceramic Materials ». Advanced Materials Research 770 (septembre 2013) : 64–67. http://dx.doi.org/10.4028/www.scientific.net/amr.770.64.
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This research has an objective to develop and fabricate thermoelectric generator (TEG) from the p-Ca3Co4O9 and n-CaMnO3 ceramic materials. The p-n materials were cut and polished to the dimension of 4 × 4 × 4 mm3 and 71 couples. The relationship between temperature difference and electrical voltage, electrical current, electrical power and conversion efficiency were measured. The electricity and efficiency of TEG showed the maximum value of 1.6 V, 300 mA, 480 mW and 0.025 % at temperature difference of 60 K.
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Djalal, Muhammad Ruswandi, et Faisal Faisal. « Studi Kestabilan Generator Sistem Sulselrabar (Stability Study of Sulselrabar System Generator) ». JEEE-U (Journal of Electrical and Electronic Engineering-UMSIDA) 3, no 1 (3 avril 2019) : 82. http://dx.doi.org/10.21070/jeee-u.v3i1.2067.
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In the standard operating system, the input parameters such as changes in the mechanical torque of the turbine and changes in the field voltage of the amplifier from the exciter need to be considered. Some studies that can be done include the study of the dynamic stability of synchronous generators when dealing with small changes that occur using the eigenvalue approach which is the roots of the characteristic equations of the system state space equation. The eigenvalue can show information on system stability and is related to the response of time to changes in the system. The system used is in the Sulselrabar electrical system. From the simulation results show the characteristics of the system in terms of the frequency response and angle of the generator rotor. For the eigenvalue system value in the inter-area oscillation mode is -0.33293 + 4.0844i, for the oscillation mode it is -0.9043 + 7.9670i. While the generator frequency response, where oscillations occur before reaching steady state conditions. The biggest overshoot response occurs in Old Tello plants, with a maximum overshoot of 0.09124 pu and a minimum of -0.2227 pu. While the smallest overshoot response is found in the Bakaru hydroelectric power plant which is equal to 0.004681 maximum pu and -0.02563 minimum pu.
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Reis, Márcio Rodrigues da Cunha, Wanderson Rainer Hilário De Araújo et Wesley Pacheco Calixto. « Efficiency Improvement of Switched Reluctance Generator Using Optimization Techniques ». Transactions on Environment and Electrical Engineering 2, no 1 (14 mars 2017) : 74. http://dx.doi.org/10.22149/teee.v2i1.91.
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This article introduces the switched reluctance machine operating as a generator. This kind of electrical machine delivers CC power at the output and the energy generated can be controlled through several variables. In this work, the switching angles of the machine's power converter are optimized using deterministic and heuristic techniques so that the output power is kept constant via PI controller while guaranteeing maximum value for machine performance, even for different excitation values and mechanical power on the shaft.
Livres sur le sujet "Maximum value generator"
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Hadfield, Andrew. Rhetoric, Commonplacing, and Poetics. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198789468.003.0005.
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Chapter 4 examines a variety of treatises and debates about rhetoric and its value, and whether the art of persuasion could be a dangerous tool in the hands of the unscrupulous or even whether it was a skill that risked corrupting the user, dangers that were identified by Quintilian, whose Institutio Oratoria (The Orator’s Education) shaped so much rhetorical theory and practice in the Renaissance. The chapter explores the practice of commonplacing, noting down particular maxims which could then serve as the basis of explorations of issues, a practice that, like rhetoric, generated anxiety about truth, falsehood, and lying. Particular attention is paid to Erasmus’s Colloquies and Lingua; William Baldwin’s A Treatise of Moral Philosophy, the most popular work of philosophy in sixteenth-century England; the use of commonplaces in Montaigne’s Essays; George Puttenham’s use of proverbs and figures in his Arte of English Poesie (1589); and Sir Philip Sidney’s understanding of poetry as lying in The Defence of Poetry.
Chapitres de livres sur le sujet "Maximum value generator"
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Dragomir, Toma-Leonida, Flavius-Maxim Petcuţ et Adrian Korodi. « Reference Value Generator of Maximum Power Point Coordinates of the Photovoltaic Panel External Characteristic ». Dans Studies in Computational Intelligence, 71–96. Berlin, Heidelberg : Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-28959-0_5.
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Xu, Liu-Jun, et Ji-Ping Huang. « Theory for Thermal Wave Nonreciprocity : Angular Momentum Bias ». Dans Transformation Thermotics and Extended Theories, 277–90. Singapore : Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-5908-0_20.
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AbstractIn this chapter, we demonstrate that an angular momentum bias generated by a volume force can also lead to modal splitting in convection-diffusion systems but with different features. We further reveal the thermal Zeeman effect by studying the temperature field propagation in an angular-momentum-biased ring with three ports (one for input and two for output). With an optimal volume force, temperature field propagation is allowed at one output port but isolated at the other, and the rectification coefficient can reach a maximum value of 1. The volume forces corresponding to the rectification coefficient peaks can also be quantitatively predicted by scalar (i.e., temperature) interference. Compared with existing mechanisms for thermal nonreciprocity, an angular momentum bias does not require temperature-dependent and phase-change materials, which has an advantage in wide-temperature-range applicability. These results may provide insights into thermal stabilization and thermal topology. The related mechanism is also universal for other convection-diffusion systems such as mass transport, chemical mixing, and colloid aggregation.
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« Indirect Power Control (IDPC) of DFIG Using Classical & ; Adaptive Controllers Under MPPT Strategy ». Dans Improved Indirect Power Control (IDPC) of Wind Energy Conversion Systems (WECS), sous la direction de Fayssal Amrane et Azeddine Chaiba, 26–85. BENTHAM SCIENCE PUBLISHERS, 2019. http://dx.doi.org/10.2174/9789811412677119010005.
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In this chapter, we present a comparative study of conventional Indirect Power Control (IDPC) algorithm of DFIG-Wind turbine in grid-connection mode, using PI and PID controllers via Maximum power point tracking (MPPT) strategy. Firstly, the conventional IDPC based on PI controllers will be described using simplified model of DFIG through stator flux orientation and wind-turbine model. The MPPT strategy is developed using Matlab/Simulink® with two wind speed profiles in order to ensure the robustness of wind-system by maintaining the Power coefficient (Cp) at maximum value and reactive power at zero level; regardless unexpectedF wind speed variation. Secondly, the rotor side converter (RSC) and Grid side converter (GSC) are illustrated and developed using Space vector modulation (SVM) in order to minimize the stress and the harmonics and to have a fixed switching frequency. In this context, the switching frequency generated by IDPC to control the six IGBTs of the inverter (RSC), and this control algorithm works under both Sub- and Supersynchronous operation modes and depending to the wind speed profiles. The quadrants operation modes of the DFIG are described in details using real DFIG to show the power flow under both modes (motor and generator in the four (04) quadrants. Finally, the conventional IDPC have several drawbacks as: response time, power error and overshoot. In this context, the PID and MRAC (adaptive regulator) controllers are proposed instead of the PI to improve the wind-system performances via MPPT strategy with/without robustness tests. The obtained simulation results under Matlab/Simulink® show high performances (in terms of power error, power tracking and response time) in steady and transient states despite sudden wind speed variation, whereas big power error and remarkable overshoot are noted using robustness tests, so the proposed IDPC can not offer big improvement under parameter variation.
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CHEBABHI, Ali. « A Novel IDPC using Suitable Controllers (Robust and Intelligent Controllers) ». Dans Improved Indirect Power Control (IDPC) of Wind Energy Conversion Systems (WECS), 86–120. BENTHAM SCIENCE PUBLISHERS, 2019. http://dx.doi.org/10.2174/9789811412677119010006.
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This chapter presents an improved Indirect power control (compared to the conventional one illustrated in chapter: 03) based on robust and suitable controllers (Robust and Intelligent controllers) to control the d-q axes currents (Ird and Irq) respectively. In order to overcome the speed/efficiency trade-off and divergence from peak power under fast variation of wind speed; three intelligent controllers (based on, T1-FLC, T2-FLC and NFC) are proposed to control the rotor direct and quadrature currents (Ird and Irq) instead of PID controllers, for grid-connected doubly fed induction generator (DFIG). The same wind-turbine (DFIG (4kW) and turbine (4.5 kW)) used in last chapter will be developed again in order to make a comparative study between the wind-system performance algorithms. The SVM strategy (to ensure the fixed switching frequency and to minimize the harmonics) is used in RSC for switching signals generation to control the inverter. In this chapter, mathematical model of each proposed controller is described in detail. The MPPT strategy is also developed in the three proposed algorithms in order to extract the maximum wind power by keeping the reactive power equal to zero value. The main aim of the proposed control is to improve the wind system performance despite the sudden wind speed variation and the DFIG’s parameter variation in transient and steady states. The simulation results using the Matlab/Simulink environment (under three proposed modes and using robustness tests) show that the intelligent controller offered high power quality in spite of wind-speed variation have superior dynamic performance and are more robust during parameter variation.
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Surendra H J et Vinod B R. « Experimental Study of Discharge Variability on Impact Coefficient of Jet for Sustainable Development ». Dans Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde220848.
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Fluid flow emerges with high velocity referred as liquid jet. Water Jet having its applications in many fields includes agriculture and power generation and it has been widely utilized. Impact value of the jet is highly important, to generate maximum efficiency in operation. Many factors influence the impact value of jet and it depends on type of vane used such as: Flat, hemispherical, curved etc. The aim of this work is to investigate the impact coefficient of jet for various discharges by comparing theoretical forces as well as forces developed through experiments for different target vanes. A systematic estimation of theoretical forces, experimental forces and its error was done in this experiment. For this purpose, weigh balance, target plates, vanes, recirculation pipes and Rotameter were used. Result of this study indicate: discharge variability influences the impact value and for a particular discharge obtained values are within the limit.
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Koh, Yun Sing, Nathan Rountree et Richard O’Keefe. « Finding Non-Coincidental Sporadic Rules Using Apriori-Inverse ». Dans Data Warehousing and Mining, 3222–34. IGI Global, 2008. http://dx.doi.org/10.4018/978-1-59904-951-9.ch204.
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Discovering association rules efficiently is an important data mining problem. We define sporadic rules as those with low support but high confidence; for example, a rare association of two symptoms indicating a rare disease. To find such rules using the well-known Apriori algorithm, minimum support has to be set very low, producing a large number of trivial frequent itemsets. To alleviate this problem, we propose a new method of discovering sporadic rules without having to produce all other rules above the minimum support threshold. The new method, called Apriori-Inverse, is a variation of the Apriori algorithm that uses the notion of maximum support instead of minimum support to generate candidate itemsets. Candidate itemsets of interest to us fall below a maximum support value but above a minimum absolute support value. Rules above maximum support are considered frequent rules, which are of no interest to us, whereas rules that occur by chance fall below the minimum absolute support value. We define two classes of sporadic rule: perfectly sporadic rules (those that consist only of items falling below maximum support) and imperfectly sporadic rules (those that may contain items over the maximum support threshold). This article is an expanded version of Koh and Rountree (2005).
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Mengersen, Kerrie, et Christopher H. Schmid. « Maximum Likelihood Approaches to Meta-analysis ». Dans Handbook of Meta-analysis in Ecology and Evolution. Princeton University Press, 2013. http://dx.doi.org/10.23943/princeton/9780691137285.003.0010.
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This chapter discusses an alternative, more general approach based on maximizing the likelihood of the data; that is, for a model with unknown parameters, finding the parameter values that are “most likely” to generate the observed data set. For example, suppose that we are interested in the overall age of a population of people, and we have only two options: 30 years and 100 years. Now suppose that we observe a random sample of people with average age of 20 years. Then this sample is more likely to have been observed if the overall age of the population is 30 years as opposed to 100 years. Of course, we have made many assumptions in this example, and in practice there is more information about parameter values and the observed sample. The chapter describes this more general setup in the context of meta-analysis and then gives some worked examples.
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Sarkar, Arindam, et Jyotsna Kumar Mandal. « Particle Swarm Optimization-Based Session Key Generation for Wireless Communication (PSOSKG) ». Dans Advances in Computational Intelligence and Robotics, 640–77. IGI Global, 2015. http://dx.doi.org/10.4018/978-1-4666-8291-7.ch020.
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In this chapter, a Particle Swarm Optimization-Based Session Key Generation for wireless communication (PSOSKG) is proposed. This cryptographic technique is solely based on the behavior of the particle swarm. Here, particle and velocity vector are formed for generation of keystream by setting up the maximum dimension of each particle and velocity vector. Each particle position and probability value is evaluated. Probability value of each particle can be determined by dividing the position of a particular particle by its length. If probability value of a particle is less than minimum probability value then a velocity is applied to move each particle into a new position. After that, the probability value of the particle at the new position is calculated. A threshold value is selected to evaluate against the velocity level of each particle. The particle having the highest velocity more than predefined threshold value is selected as a keystream for encryption.
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Pradhan, Manaswini. « Indian Healthcare Service Management Through Data Mining ». Dans Next-Generation Mobile and Pervasive Healthcare Solutions, 219–33. IGI Global, 2018. http://dx.doi.org/10.4018/978-1-5225-2851-7.ch014.
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The main intention of our method is to provide better Healthcare services over the rural areas in terms of prediction of the chief hospitals with required basic facilities around that particular area. Accordingly, a Questionnaire survey is made for collecting the relevant hospital data around the Odisha region. Then, the concept of data mining is utilized in order to extract the data from the Questionnaire. Further, Incremental Spanning algorithm is introduced here for the mining of data from the Questionnaire. In the Questionnaire, appropriate score values were assigned for each category based on the requirement. Moreover, the hospital satisfying all the required components within the Questionnaire have to be determined for predicting the better hospitals. The Genetic Algorithm is introduced so as to determine the maximum of the score values obtaining for the input hospital data. Finally, the ranking of first five supreme hospitals is determined around the Odisha region.
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Kwaśnicki, Paweł. « IIIrd Generation Solar Cell ». Dans Solar Cells [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.95289.
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Light harvesting for generation of electric energy is one of the most important research topics in applied sciences. First, for an efficient harvesting one needs a material with a broad light absorption window having a strong overlap with the sunlight spectrum. Second, one needs an efficient conversion of photoexcited carriers into produced current or voltage which can be used for applied purposes. The maximum light conversion coefficient in semiconductor systems is designated by so called Shockley-Queisser law, which is around 32% for an optimal bandgap value of 1,2–1,3 eV. However the efficiency may be increased using a solutions based on semiconductor nano materials such as quantum dots. Solar cells based on such a structures are included in the group of 3rd generation solar sell. 3rd generation solar cell encompasses multiple materials as a base of cell, such as: perovskite, organic, polymers and biomimetics. The most promising and in the same time most discussed are quantum dots and perovskite. Both material has a potential to revolutionize the solar cell industry due to their wide absorption range and high conversion coefficient. Nonetheless before the most common used material in photovoltaic namely silicon is replace one must overcome few major issues such as: stability and lifetime for at least 5 to 10 years or more, manufacturing process for a large surfaces and low production cost as well as recycling after the time of optimal use.
Actes de conférences sur le sujet "Maximum value generator"
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Herna´ndez, Jorge I., Claudio A. Estrada, Roberto Best et Rube´n J. Dorantes. « Study of a Solar Booster Assisted Ejector Refrigeration System With R134a ». Dans ASME 2003 International Solar Energy Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/isec2003-44242.
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A parametric study for a booster assisted ejector refrigeration system in steady state is carried out employing Lu’s ejector model in transition regime. The range of generator and condenser temperatures is considered for a solar powered system. Conceiving the ejector geometry, through the area ratio φ and the main throat area A*, and the system behavior, through the energy efficiency COPs, the exergy efficiency εs and energy ratio Er, it was found that their extreme values, lowest for A* and highest for the remainder, are reached at the highest generator temperature, TGE, and booster discharge pressure, pDIS, with the lowest condenser temperature, TCO, for the considered evaporator temperature, TEV, of −10°C. In regard to the ejector behavior, its maximum efficiency value, ηEJ, is reached for the highest TGE and the lowest TCO for an intermediate pDIS. If TCO is increased, the maximum ηEJ value is achieved at a higher pDIS. In spite of that the maximum ηEJ value is not reached at the highest pDIS, its influence is not reflected in system behavior because U always increases and its maximum value agrees with theory. The most important system and ejector parameters are presented as a reference.
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Hoffman, John S., et William L. Kopko. « Maximizing Asset Value of Combustion Turbines ». Dans ASME Turbo Expo 2003, collocated with the 2003 International Joint Power Generation Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/gt2003-38012.
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An, improved gas-turbine supercharging technology [1–3], newly patented, uses variable supercharging with enhanced fogging or evaporative cooling (enhanced supercharging) to sustain mass density through a turbine system at maximum allowable level for the supercharged turbine, allowing output similar to that available normally at cold weather and sea level conditions all year long. Using variable pitch fans to modulate pressure increases, enhanced supercharging increases pressures to restore mass flow levels as high as possible without surpassing torque limits on the shaft or other constraining factors, such as generator capacity. Increased fogging then removes sensible heat added by the fan, essentially straight lining output throughout the year at the maximum output for which the turbine system has been designed. Largest increases in output occur on the hottest days, but significant increases also occur at ISO conditions and below. Achievable increments of net output on a peak summer day can be nine times higher than fogging alone, the currently preferred augmentation mode for combustion turbines. Enhanced supercharging increases shareholder value by maximizing the increase in economic value added (EVA) for combustion turbine assets [4]. Under EVA, an investment that returns 9% when the cost of capital is 9% would be counted as adding no increment of profit or value to a company. Whether a combustion turbine has an augmentation system or has none, enhanced supercharging almost always adds significant EVA. The EVA for enhanced supercharging often exceeds other options by an order of magnitude. Enhanced supercharging produces greatest profits on combined-cycle plants, although it will also produce additional EVA on many simple-cycle engines. As the power industry struggles to return to profitability, enhanced supercharging offers a simple and straightforward means to increase shareholder value, returning on average 15 times the economic value added of investments in base power plants. For new plants, the increment of value may be sufficient to turn a “no-go” into a “go” decision. For existing plants enhanced supercharging can to turn a lackluster financial year into a profitable one.
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Qi, Shuang, Wenxin Xiang, Ping Huang, Fangmao Ning, Minyu Fan, Lei Qi, Mingya Chen et Jun Xu. « Crack Propagation Analysis of Dissimilar Metal Weld for Steam Generator Nozzle Safety End ». Dans 2022 29th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/icone29-93289.
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Abstract According to the design load of steam generator, fatigue crack propagation of dissimilar metal weld joint were considered for the steam generator nozzle safety end of third generation pressurized water reactor (PWR) nuclear power unit. Based on finite element analysis, crack propagation analysis was carried out on dissimilar metal welds at the safety end of the circumferential plane crack joints on the inner surface of ellipse with a depth of 20 mm and a length of 120 mm. The mechanical response of the structures with defects was calculated in transient state of each design, and meanwhile the crack propagation was calculated during the whole lifetime. The fracture safety margin at the end of life of the component was verified. The results showed that, the maximum expansion of dissimilar metal weld was 2.2 mm in the direction of crack depth at the end of life, and then the fracture safety margin met the design specifications. In consequence, it provided theoretical basis and technical support for the acceptance of service defects of the third generation PWR nuclear power units, and even provided strong theoretical, methodological and data support for the structural integrity assessment of nuclear power plants, which had important theoretical significance and engineering application value.
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Cau, Giorgio, Daniele Cocco, Pamela Concas et Vittorio Tola. « Integration of Combined Cycle Power Plants and Parabolic Solar Troughs Using CO2 as Heat Transfer Fluid ». Dans ASME Turbo Expo 2010 : Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-22886.
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In this paper, a performance assessment of integrated solar combined cycle systems (ISCCS) is reported on. The main aim of the study was to evaluate the solar conversion efficiency of ISCCS plants based on parabolic troughs using CO2 as heat transfer fluid. The use of CO2 instead of the more conventional thermal oil as heat transfer fluid can allow an increase in the trough outlet temperature and thus in solar energy conversion efficiency. In particular, the ISCCS plant considered here was developed on the basis of a triple-pressure, reheated combined cycle power plant rated at 252 MW. Two different solutions for the solar steam generator are considered and compared. Moreover, the performance of the ISCCS system was evaluated with reference to different values of CO2 maximum temperature, solar radiation and solar share of the power output. The results of the performance assessment show that the solar energy conversion efficiency ranges from 23% to 25% for a CO2 maximum temperature of 550°C. The use of a CO2 temperature of 450°C reduces the solar efficiency by about 1.5–2.0 percentage points. The use of a solar steam generator including only the evaporation section instead of the preheating, evaporation and superheating sections allows the achievement of slightly better conversion efficiencies. However, the adoption of this solution leads to a maximum value of the solar share around 10% on the ISCCS power output. The solar conversion efficiencies of the ISCCS systems considered here are better than those of the more conventional Concentrating Solar Power (CSP) systems based on steam cycles (14–18%) and are very similar to the predicted conversion efficiencies of the more advanced direct steam generation plants (22–27%).
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Banerjee, Srijan, Parnab Saha, Bishaljit Paul et Chandan Kumar Chanda. « ALLOCATING THE VARIABLE COST OF TRANSMISSION LINES DUE TO ELASTIC LOADS IN A CONGESTED POWER MARKET ». Dans Topics in Intelligent Computing and Industry Design. volkson press, 2020. http://dx.doi.org/10.26480/cic.01.2020.99.102.
Texte intégralRésumé :
In a competitive power market, the elastic demand for electrical energy transmission is viewed as a prime competitor of generator. Remote generators are needed for transmission to compete with local generators. The value of the transmission is based on the difference of Locational Marginal Price (LMP) of the generators across the network. To maintain the well operation of power market, LMPs which provide the price sensitivity is calculated at every bus. The revenue collected by the transmission owners is a convex quadratic function of the amount of power transmitted. This revenue provides a sound impact on investment perspective for setting the price that producers and customers should pay for the network. In this paper for a three bus system, the LMPs are calculated at the buses and a demand function for the transmission has been modeled which computes the maximum revenue for the optimal transmission capacity in the syste.
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Jiang, Dongxiang, Liangyou Hong, Zheng Wang et Xiaorong Xie. « Torsional Vibration Analysis and Stress Calculation for the Fault 600MW Steam Turbine Generator Shaft System ». Dans ASME 2009 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/detc2009-86854.
Texte intégralRésumé :
Subsynchronous oscillation (SSO) or torsional vibration may cause shaft of steam turbine generator hurt heavily. This phenomenon has destroyed two generator shafts in one of China’s power plant in 2008. Detailed analysis and several measurements have been taken to identify the reason of the accident. First, the operational data is analyzed, including field torsional vibration dada. Then, the modal of the shaft system is calculated. Each torsional vibration frequency is gotten with corresponding modal shape. Dangerous location of the shaft system is obtained. Third, torque value of different operation condition is calculated based on two different models: one is traditional multiple mass element rotor dynamic model and the other is an four mass element electromechanical model of rotor oscillation. Following, the maximum stress on the dangerous location is calculated using finite element method. Finally, the root cause of shaft destruction is analyzed and identified.
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Hamada, Hirotsugu, Akikazu Kurihara et Masahiro Nishimura. « Study of Thermal Influence on Tubes Due to Sodium-Water Reactions in LMFBR Steam Generator ». Dans 12th International Conference on Nuclear Engineering. ASMEDC, 2004. http://dx.doi.org/10.1115/icone12-49064.
Texte intégralRésumé :
A study of thermal influence on heat-transfer tubes in sodium-water reactions is carried out to evaluate the tube rupture due to overheating in the water leak accident of an LMFBR steam generator (SG). By assuming the sodium-water reaction jet to be a two-phase flow that consists of sodium and hydrogen, the heat-transfer characteristics are examined and a simple model of effective heat-transfer coefficient (HTC) is proposed for the safety evaluation of the SG. Comparison of the model with experimental data leads to the following conclusions: An upper limit exists in the HTC between reaction jet and tube wall, and it is equivalent in approximation to the HTC of single-phase sodium flow. The HTC can be written in simple form as functions of the HTC of single-phase sodium flow, void fraction and temperatures of sodium, hydrogen and tube wall. Hydrogen provides negligible heating effect, so that the apparent HTC would decrease with increase of the hydrogen temperature that can readily surpass that of sodium. The outer-surface temperature of tube wall would not rise so high beyond the temperature of sodium that is excellent in heat-transfer characteristics, even if tube wall is exposed to the high-temperature hydrogen. The transient heat conduction analysis with the mean value of the data can appropriately evaluate the outer-surface temperature of tube wall by the metallographic observation, while the analysis with the maximum value can conservatively evaluate the tube wall temperature.
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Sakai, Michiya, Kenji Kanazawa et Yasuki Ohtori. « Development of High Acceleration Shaking Table System Using Resonance Vibration ». Dans ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-63752.
Texte intégralRésumé :
High acceleration shaking table system to be called “Strong Shake Generator” (SSG) using resonance vibration has been developed. New concept of setting the resonance table on outside shaking table is devised. Maximum acceleration of 200 m/s2 with 5 ton specimen weight is achieved. At the trial operation of SSG, the environmental influence exceeding the regulation value of vibration level has been occurred at the site boundary of CRIEPI. In order to suppress vibration of SSG, the semi-active mass damper (SAMD) has been additionally installed on base of shaking table. Vibration of SSG was reduced by counterforce of the SAMD. For the confirmation of the earthquake-proof safety for various nuclear facilities, strong shake generator will be utilized.
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Gravråkmo, Halvar, Erland Strömstedt, Andrej Savin, Olle Svensson et Mats Leijon. « Measurements of Extreme Forces on a Wave Energy Converter of Point Absorber Type and Estimation of Added Mass of Cylindrical Buoy ». Dans ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/omae2014-24263.
Texte intégralRésumé :
A wave energy converter (WEC) of point absorber type is tested at the west coast of Sweden. The buoy is a vertical cylinder. The linear generator on the seabed has limited stroke length. Large waves cause the generator to reach its maximum stroke length. As this happen, a spring in the generator is compressed, causing the buoy to instantly come to rest. During this process the force between the buoy and the generator is measured. Also the acceleration of the buoy is measured. This process and the extreme forces on the generator hull is described and the study shows that the magnitude of this force is greatly influenced by the added mass of the buoy and thus the buoy geometry. The ratio between the extreme forces on the hull and the forces during normal operation will affect the dimensioning and economy of the WEC. Force acting between generator and buoy were measured during various events as the WEC was operating. Heave added mass was derived from the measurements and found to be greater than the theoretical value.
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Nam, Hyungseok, Amado Maglinao et Sergio Capareda. « Fluidized Bed Air Gasification Using Low Heating Value Sand-Bedded Dairy Manure and Sludge Pellets ». Dans ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-50513.
Texte intégralRésumé :
Solid manure handling is a major environmental issue confronting animal facilities in the United States. One difficulty in using dairy manure as a fuel source is the presence of sand bedding used for lactating dairy cows. More than 30% of dairy farms use sand beds for a dry and clean environment that prevents bacterial growth [1]. In this study, dairy animal manure obtained directly from waste lagoons was used for the air gasification process. The manure was dried to reduce the moisture down to 5% and a sand separating system was designed to remove some sand bedding materials. Preliminary air gasification experiments showed that the direct use of dairy manure containing 75% ash content, that reflect high sand content, reduced the temperature of the reactor. The study is also aimed at handling unprocessed dairy manure and generating electric power for the on-site use. A high heating value manure is needed to run the gasifier and the produced synthesis gas (or syngas) is fed to an engine coupled with a generator. Some dairy manure gasification work were done using fresh dairy manure. The highest heating value from the dairy manure biomass was found to be 4.5MJ/kg in a fixed-bed gasifier [2]. Another gasification study using a fluidized-bed reactor could produce syngas heating value as high as 4.7MJ/m3 from dairy manure [3]. A bench-scale fluidized bed containing a 3-inch diameter reactor tube with a cyclone and a scrubber was used to gasify dairy manure using air at different temperatures. The sand separated dairy manure used in this study contained approximately 45% ash content. The maximum heating value of the synthesis gas was 3.8MJ/m3 at an operating temperature of 750°C. The syngas will need to be upgraded. To upgrade the synthesis gas heating value, sludge pellets of 18.7MJ/kg were mixed with the dairy manure in different ratios of 10% and 30%. The syngas heating values from mixed manure with sludge pellet were increased to 5MJ/m3 with 10% sludge, and 5.7MJ/m3 with 30% sludge. The sludge used has higher heating value resulting in higher gas HV. The cold gasification efficiency was achieved as high as 36±5% with dairy manure mixed with sludge pellet. At a higher operating temperature, higher efficiency was obtained with increased gas composition of hydrogen and carbon monoxide. This syngas may then be used for power generation as well as possible input gas for the Fisher Tropsch process for liquid biofuel production. The result of the experiments will be a cornerstone for the widespread application of low heating value animal waste for producing high heating value syngas that may be used for electric power generation as a result of various upgrading processes.