A comparative study of solar heliostat assisted supercritical CO2 recompression Brayton cycles: Dynamic modelling and control strategies

2017 ◽  
Vol 120 ◽  
pp. 113-124 ◽  
Author(s):  
Dia Milani ◽  
Minh Tri Luu ◽  
Robbie McNaughton ◽  
Ali Abbas
2002 ◽  
Vol 26 (4) ◽  
pp. 191-210 ◽  
Author(s):  
Anca D. Hansen ◽  
Poul Sørensen ◽  
Frede Blaabjerg ◽  
John Becho

This paper describes a dynamic model of a wind farm and its nearest utility grid. It is intended to use this model in studies addressing the dynamic interaction between a wind farm and a power system, both during normal operation of the wind farm and during transient grid fault events. The model comprises the substation where the wind farm is connected, the internal power collection system of the wind farm, the electrical, mechanical and aerodynamic models for the wind turbines, and a wind model. The integrated model is built to enable the assessment of power quality and control strategies. It is implemented in the commercial dedicated power system simulation tool DIgSILENT.


Author(s):  
Timothy C. Allison ◽  
J. Jeffrey Moore ◽  
Doug Hofer ◽  
Meera Day Towler ◽  
Joseph Thorp

Supercritical CO2 power cycles incorporate a unique combination of high fluid pressure, temperature, and density as well as limited component availability (e.g., high-temperature trip valves) that can result in operational challenges, particularly during off-design and transient operation. These conditions and various failure scenarios must be considered and addressed during the facility, component, and control system design phase in order to ensure machinery health and safety during operation. This paper discusses significant findings and resulting design/control requirements from a detailed failure modes and effects analysis (FMEA) that was performed for the 1 MWe-scale supercritical CO2 test loop at Southwest Research Institute, providing insight into design and control requirements for future test facilities and applications. The test loop incorporates a centrifugal pump, axial turboexpander, gas-fired primary heat exchanger, and microchannel recuperator for testing in a simple recuperated cycle configuration at pressures and temperatures up to 255 bar and 715 °C, respectively. The analysis considered off-design operation as well as high-impact failures of turbomachinery and loop components that may require fast shutdowns and blowdowns. The balance between fast shutdowns/blowdowns and the need to manage thermal stresses in the turbomachinery resulted in staged shutdown sequences and impacted the design/control strategies for major loop components and ancillary systems including the fill, vent, and seal supply systems.


Author(s):  
Timothy C. Allison ◽  
J. Jeffrey Moore ◽  
Doug Hofer ◽  
Meera Day Towler ◽  
Joseph Thorp

Supercritical CO2 power cycles incorporate a unique combination of high fluid pressure, temperature, and density as well as limited component availability (e.g., high-temperature trip valves) that can result in operational challenges, particularly during off-design and transient operation. These conditions and various failure scenarios must be considered and addressed during the facility, component, and control system design phase in order to ensure machinery health and safety during operation. This paper discusses significant findings and resulting design/control requirements from a detailed failure modes and effects analysis that was performed for the 1 MWe-scale supercritical CO2 test loop at Southwest Research Institute, providing insight into design and control requirements for future test facilities and applications. The test loop incorporates a centrifugal pump, axial turboexpander, gas-fired primary heat exchanger, and micro-channel recuperator for testing in a simple recuperated cycle configuration at pressures and temperatures up to 255 bara and 715°C, respectively. The analysis considered offdesign operation as well as high-impact failures of turbomachinery and loop components that may require fast shutdowns and blowdowns. The balance between fast shutdowns/blowdowns and the need to manage thermal stresses in the turbomachinery resulted in staged shutdown sequences and impacted the design/control strategies for major loop components and ancillary systems including the fill, vent, and seal supply systems.


Author(s):  
Diego R. Higueras-Ruiz ◽  
Kiisa Nishikawa ◽  
Heidi Feigenbaum ◽  
Michael Shafer

Abstract Interest in emulating the properties of biological muscles that allow for fast adaptability and control in unstructured environments has motivated researchers to develop new soft actuators, often referred to as ‘artificial muscles’. The field of soft robotics is evolving rapidly as new soft actuator designs are published every year. In parallel, recent studies have also provided new insights for understanding biological muscles as ‘active’ materials whose tunable properties allow them to adapt rapidly to external perturbations. This work presents a comparative study of biological muscles and soft actuators, focusing on those properties that make biological muscles highly adaptable systems. In doing so, we briefly review the latest soft actuation technologies, their actuation mechanisms, and advantages and disadvantages from an operational perspective. Next, we review the latest advances in understanding biological muscles. This presents insight into muscle architecture, the actuation mechanism, and modeling, but more importantly, it provides an understanding of the properties that contribute to adaptability and control. Finally, we conduct a comparative study of biological muscles and soft actuators. Here, we present the accomplishments of each soft actuation technology, the remaining challenges, and future directions. Additionally, this comparative study contributes to providing further insight on soft robotic terms, such as biomimetic actuators, artificial muscles, and conceptualizing a higher level of performance actuator named artificial supermuscle. In conclusion, while soft actuators often have performance metrics such as specific power, efficiency, response time, and others similar to those in muscles, significant challenges remain when finding suitable substitutes for biological muscles, in terms of other factors such as control strategies, onboard energy integration, and thermoregulation.


1993 ◽  
Vol 46 (11S) ◽  
pp. S165-S172
Author(s):  
A. Ercoli-Finzi ◽  
P. Mantegazza

In this work the dynamics of a manipulator arm is analyzed by Maggi’s formulation and by automatic development of the equations of motion. Two control strategies, that is an adaptive and a standard one, are taken into account in order to satisfactory perform pick and place maneuvers. Numerical simulations emphasize performance qualities and limits of the two choices and suggest a possible implementation of mixed control strategies.


Solar Energy ◽  
2015 ◽  
Vol 119 ◽  
pp. 507-530 ◽  
Author(s):  
Forough Parvareh ◽  
Dia Milani ◽  
Manish Sharma ◽  
Matteo Chiesa ◽  
Ali Abbas

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