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A J Clemmens - One of the best experts on this subject based on the ideXlab platform.
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Downstream Water Level control test results on the wm lateral canal
Journal of Irrigation and Drainage Engineering-asce, 2010Co-Authors: A J Clemmens, R J StrandAbstract:On steep canals, distant Downstream-Water-Level control can be challenging. The Software for Automated Canal Management was developed, in part, to test various distant Downstream Water-Level controllers. It was implemented on the WM canal of the Maricopa Stanfield Irrigation and Drainage District, Stanfield, Ariz. to compare the performance of various controllers. In 2004, Clemmens and Schuurmans used optimization to determine the coefficients for a variety of controllers. These controllers vary in their complexity from a series of simple, single-input-single-output, proportional-integral controllers to a fully centralized, multiple-input-multiple-output, optimal controller. The controller design also varies regarding which pools are under Downstream, or upstream, control and according to the conditions (e.g., flow rate) assumed for controller design. These controllers were tested under actual operating conditions and with unscheduled disturbances. The results of these tests are presented in this paper.
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automatic Downstream Water Level feedback control of branching canal networks theory
Journal of Irrigation and Drainage Engineering-asce, 2006Co-Authors: Brian Wahlin, A J ClemmensAbstract:Most of the research on the design of feedback controllers for irrigation canals has been concentrated on single, in-line canals with no branches. Because the branches in a network are hydraulically coupled with each other, it may be difficult to automatically control a branching canal network by designing separate feedback controllers for each branch and then letting them run simultaneously. Thus feedback control of an entire branching canal system may be more efficient if the branching flow dynamics are explicitly taken into account during the feedback controller design process. This paper develops two different feedback controllers for branching canal networks. The first feedback controller was developed using linear quadratic regulator theory and the second using model predictive control. Both algorithms were able to effectively control a simple branching canal network example with relatively small flow changes.
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automatic Downstream Water Level feedback control of branching canal networks simulation results
Journal of Irrigation and Drainage Engineering-asce, 2006Co-Authors: Brian Wahlin, A J ClemmensAbstract:Previous research on canal automation has dealt with the control of single, in-line canals, while canal operators typically have to control an entire network of canals. Because the branches in a network are hydraulically coupled with each other, control of a branching canal network based on separate controllers for each branch may not be the most effective control strategy. A methodology by which existing automatic control systems could be modified to control branching canal networks is provided in a companion paper. This paper presents results of hydraulic simulations of the new methodology to estimate the controllability of a large portion of the branching canal network operated by the Salt River Project (SRP). Two types of controllers were used for this study: (1) linear quadratic regulator (LQR) and (2) model predictive control (MPC). Both controllers used the same underlying process model [integrator-delay (ID) model], and both controllers were capable of feedback and feedforward control. Under feedback control alone, both controllers gave similar performance, but were unable to effectively control the overall system because of the long delay times. When feedforward control was added to the feedback controller, both of these control systems were able to effectively control the branching canal network operated by SRP. For the LQR controller, the volume compensation method for routing known demand change was used as the feedforward controller. For the MPC controller, the ID model was used as the feedforward controller. Slight differences were noted between the performance of the two feedforward controllers.
Nehudek Adam - One of the best experts on this subject based on the ideXlab platform.
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Hollow cone valve capacity in the restricted outflow conditions
Vysoké učení technické v Brně. Fakulta stavební, 2015Co-Authors: Nehudek AdamAbstract:The thesis aims to determine the influence partial or complete submerge of hollow cone valve by outflow on its capacity without space restrictions, by outflow into discharge chamber and by outflow into Water tunnel of circular cross section. The valve capacity is for mutual comparability purposes usually characterized by discharge coefficient. Research works have been performed on a spatial hydraulic model of the valve with inlet diameter D = 67 mm and an apex angle of a cone 90°. Values of the discharge coefficient obtained from measurements were statistically analyzed. The dependence of discharge coefficient, expressed by energy head, on submerged Level was approximated by an exponential function. Exponent value of this function express the dependance rate of valve capacity on Downstream Water Level. This procedure didn’t demonstrate signifiant dependance Downstream Water Level on hollow cone valve capacity, only on tests at outflow to Water tunel showed a low increase in the discharge coefficient partly due to the influence of kinetic energy of the stream flowing out of the tunnel on the energy head and also due to underpressure. Independence of discharge coefficient value on valve head has been prooved for head greather than 232 mm. Also was defined 3 stages of interaction outflow jet from valve and Downstream Water, some of them may cause on real Waterworks structures unfavorable situations (may affect excessive load on valve by pressure pulsations). The presented results allow better evaluation of bottom outlets capacity at higher Water Levels, when the valves are flooded. Significant effect of sufficient aeration (especially in long Water tunnels) on valve capacity was also confirmed. Taking into account on the specifics of hollow jet valves and cone valves, it is possible to generalize some of this resultos on them as well
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Hollow cone valve capacity in the restricted outflow conditions
Vysoké učení technické v Brně. Fakulta stavební, 2015Co-Authors: Nehudek AdamAbstract:Cílem diplomové práce je stanovit vliv částečného nebo úplného zatopení rozstřikovacího uzávěru dolní vodou na jeho kapacitu při výtoku bez prostorového omezení, při výtoku do usměrňovací komory a při výtoku do odpadní štoly kruhového průřezu. Kapacita uzávěru je zpravidla pro vzájemnou porovnatelnost charakterizována součinitelem výtoku. Výzkumné práce byly prováděny na prostorovém hydraulickém modelu s modelem uzávěru o vstupním průměru D = 67 mm a vrcholovým úhlem rozrážecího kužele 90°. Hodnoty součinitele výtoku získané z měření byly podrobeny statistické analýze. Závislost součinitele výtoku, vyjádřeného z energetického spádu na uzávěr, na míře zatopení byla aproximována exponenciální funkcí. Hodnota exponentu této funkce vyjadřuje míru závislosti kapacity uzávěru na zatopení dolní vodou. Tento postup neprokázal významný vliv úrovně hladiny dolní vody na kapacitu uzávěru, pouze u zkoušek výtoku do štoly došlo k mírnému navýšení součinitele výtoku jednak vlivem kinetické energie proudu odtékajícího štolou na energetický spád a jistou měrou i vlivem podtlaku. Pro spád na zkoušený uzávěr větší jak 232 mm byla prokázána automodelovost hodnoty součinitele výtoku. Dále byla definována 3 stadia interakce výtokového paprsku z uzávěru a dolní vody, některá z nich mohou být na skutečných vodních dílech provozně nepříznivá (mohou způsobovat přílišné zatížení uzávěru tlakovými pulsacemi). Předložené výsledky umožní lépe posuzovat kapacitu spodních výpustí vodních děl za vyšších vodních stavů, kdy dochází k zatopení uzávěrů dolní vodou. Také byl potvrzen významný vliv dostatečného zavzdušnění (především v dlouhých odpadních štolách) na kapacitu uzávěru. S přihlédnutím ke specifickým vlastnostem prstencových a kuželových uzávěrů lze výše uvedené poznatky do jisté míry zobecnit i na ně.The thesis aims to determine the influence partial or complete submerge of hollow cone valve by outflow on its capacity without space restrictions, by outflow into discharge chamber and by outflow into Water tunnel of circular cross section. The valve capacity is for mutual comparability purposes usually characterized by discharge coefficient. Research works have been performed on a spatial hydraulic model of the valve with inlet diameter D = 67 mm and an apex angle of a cone 90°. Values of the discharge coefficient obtained from measurements were statistically analyzed. The dependence of discharge coefficient, expressed by energy head, on submerged Level was approximated by an exponential function. Exponent value of this function express the dependance rate of valve capacity on Downstream Water Level. This procedure didn’t demonstrate signifiant dependance Downstream Water Level on hollow cone valve capacity, only on tests at outflow to Water tunel showed a low increase in the discharge coefficient partly due to the influence of kinetic energy of the stream flowing out of the tunnel on the energy head and also due to underpressure. Independence of discharge coefficient value on valve head has been prooved for head greather than 232 mm. Also was defined 3 stages of interaction outflow jet from valve and Downstream Water, some of them may cause on real Waterworks structures unfavorable situations (may affect excessive load on valve by pressure pulsations). The presented results allow better evaluation of bottom outlets capacity at higher Water Levels, when the valves are flooded. Significant effect of sufficient aeration (especially in long Water tunnels) on valve capacity was also confirmed. Taking into account on the specifics of hollow jet valves and cone valves, it is possible to generalize some of this resultos on them as well.
Brian Wahlin - One of the best experts on this subject based on the ideXlab platform.
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automatic Downstream Water Level feedback control of branching canal networks theory
Journal of Irrigation and Drainage Engineering-asce, 2006Co-Authors: Brian Wahlin, A J ClemmensAbstract:Most of the research on the design of feedback controllers for irrigation canals has been concentrated on single, in-line canals with no branches. Because the branches in a network are hydraulically coupled with each other, it may be difficult to automatically control a branching canal network by designing separate feedback controllers for each branch and then letting them run simultaneously. Thus feedback control of an entire branching canal system may be more efficient if the branching flow dynamics are explicitly taken into account during the feedback controller design process. This paper develops two different feedback controllers for branching canal networks. The first feedback controller was developed using linear quadratic regulator theory and the second using model predictive control. Both algorithms were able to effectively control a simple branching canal network example with relatively small flow changes.
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automatic Downstream Water Level feedback control of branching canal networks simulation results
Journal of Irrigation and Drainage Engineering-asce, 2006Co-Authors: Brian Wahlin, A J ClemmensAbstract:Previous research on canal automation has dealt with the control of single, in-line canals, while canal operators typically have to control an entire network of canals. Because the branches in a network are hydraulically coupled with each other, control of a branching canal network based on separate controllers for each branch may not be the most effective control strategy. A methodology by which existing automatic control systems could be modified to control branching canal networks is provided in a companion paper. This paper presents results of hydraulic simulations of the new methodology to estimate the controllability of a large portion of the branching canal network operated by the Salt River Project (SRP). Two types of controllers were used for this study: (1) linear quadratic regulator (LQR) and (2) model predictive control (MPC). Both controllers used the same underlying process model [integrator-delay (ID) model], and both controllers were capable of feedback and feedforward control. Under feedback control alone, both controllers gave similar performance, but were unable to effectively control the overall system because of the long delay times. When feedforward control was added to the feedback controller, both of these control systems were able to effectively control the branching canal network operated by SRP. For the LQR controller, the volume compensation method for routing known demand change was used as the feedforward controller. For the MPC controller, the ID model was used as the feedforward controller. Slight differences were noted between the performance of the two feedforward controllers.
Yeonwoong Choe - One of the best experts on this subject based on the ideXlab platform.
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method for operating drainage pump stations considering Downstream Water Level and reduction in urban river flooding
Water, 2021Co-Authors: Yeonmoon Choo, Jonggu Kim, Shangho Park, Taiho Choo, Yeonwoong ChoeAbstract:Korea experiences increasing annual torrential rains owing to climate change and river flooding. The government is expanding a new drainage pump station to minimize flood damage, but the river Level has not been adjusted because of torrential rains. Therefore, the river Level must be adjusted to operate the drainage pump station, and it can be adjusted through the reservoir of the drainage pump station. In this study, we developed a method for operating drainage pump stations to control the river Level and verify the effectiveness of the proposed method. A stormWater management model (SWMM) was used to simulate the Suyeong River and Oncheon River in Busan, Korea. The rainfall data from 2011 to 2021 were investigated. The data were sorted into ten big floods that occurred in Busan. The model was calibrated with actual rainfall data. The Water Level of the Suyeong River and the Oncheon River was the highest in most simulations. The simulation results showed an average decrease of 3018.2 m3 in Suyeong River flooding, and the Oncheon River needed to be supplemented due to structural problems. As a result of the recombination by simply supplementing the structural problems of the Oncheon River, the average flooding of 194.5 m3 was reduced. The proposed method is economical and efficient for reducing urban stream flooding in areas susceptible to severe damage caused by climate change.
Xianxun Wang - One of the best experts on this subject based on the ideXlab platform.
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Optimizing utility-scale photovoltaic power generation for integration into a hydropower reservoir by incorporating long- and short-term operational decisions
Applied Energy, 2017Co-Authors: Bo Yu-ming, Maoyuan Feng, Shenglian Guo, Xiaoqi Zhang, Pan Liu, Xianxun WangAbstract:The variability of photovoltaic (PV) power challenges its integration into power grids at the utility-scale. Operating PV power complementarily with hydropower is a promising way for the grid to accommodate more PV energy. This study optimizes the size of a utility-scale PV plant for integration into a hydro plant using cost–benefit analysis and considering variations in Downstream Water Level (VDWL). A nesting model that incorporates both long- and short-term operating decisions is developed to estimate the delivered PV energy. This includes a multi-objective optimization model that provides long-term decisions for the joint operation of the plants. These factors are then incorporated into a short-term simulation model, which produces successive decisions relating to power curtailment and Water Levels. Finally, the expected net revenue of the PV plant over its lifespan is calculated while constraining the VDWL to protect Downstream Water users. China's Longyangxia hydro–PV plant was selected for a case study. The results indicate that: (1) the optimal size of the PV plant is 950 MW with a maximum net revenue of 5.2 billion CNY over its lifespan; (2) the optimal PV size is sensitive to financial factors (the feed-in tariff, the initial investment, and the operation & maintenance costs); and (3) a larger reservoir storage capacity tends to be integrated with a larger PV plant. The combination of the cost-benefit analysis and the nesting model appears an effective approach to optimize the size of the PV plant being integrated with hydro plant and could equally apply to integrating other renewable energy sources.