Maximizing the power capture is an important issue to the turbines that are installed in low wind speed area. In this paper, we focused on the modeling and control of variable speed wind turbine that is composed of tw...Maximizing the power capture is an important issue to the turbines that are installed in low wind speed area. In this paper, we focused on the modeling and control of variable speed wind turbine that is composed of two-mass drive train, a Squirrel Cage Induction Generator (SCIG), and voltage source converter control by Space Vector Pulse Width Modulation (SPVWM). To achieve Maximum Power Point Tracking (MPPT), the reference speed to the generator is searched via Extremum Seeking Control (ESC). ESC was designed for wind turbine region II operation based on dither-modulation scheme. ESC is a model-free method that has the ability to increase the captured power in real time under turbulent wind without any requirement for wind measurements. The controller is designed in two loops. In the outer loop, ESC is used to set a desired reference speed to PI controller to regulate the speed of the generator and extract the maximum electrical power. The inner control loop is based on Indirect Field Orientation Control (IFOC) to decouple the currents. Finally, Particle Swarm Optimization (PSO) is used to obtain the optimal PI parameters. Simulation and control of the system have been accomplished using MATLAB/Simulink 2014.展开更多
In the face of an escalating global water crisis,countries worldwide grapple with the crippling effects of scarcity,jeopardizing economic progress and hindering societal advancement.Solar energy emerges as a beacon of...In the face of an escalating global water crisis,countries worldwide grapple with the crippling effects of scarcity,jeopardizing economic progress and hindering societal advancement.Solar energy emerges as a beacon of hope,offering a sustainable and environmentally friendly solution to desalination.Solar distillation technology,harnessing the power of the sun,transforms seawater into freshwater,expanding the availability of this precious resource.Optimizing solar still performance under specific climatic conditions and evaluating different configurations is crucial for practical implementation and widespread adoption of solar energy.In this study,we conducted theoretical investigations on three distinct solar still configurations to evaluate their performance under Baghdad’s climatic conditions.The solar stills analyzed include the passive solar still,themodified solar still coupled with a magnetic field,and themodified solar still coupled with bothmagnetic and electrical fields.The results proved that the evaporation heat transfer coefficient peaked at 14:00,reaching 25.05 W/m^(2).℃for the convention pyramid solar still(CPSS),32.33 W/m^(2).℃for the magnetic pyramid solar still(MPSS),and 40.98 W/m^(2).℃for elecro-magnetic pyramid solar still(EMPSS),highlighting their efficiency in converting solar energy to vapor.However,exergy efficiency remained notably lower,at 1.6%,5.31%,and 7.93%for the three still types,even as energy efficiency reached its maximum of 18.6%at 14:00 with a corresponding peak evaporative heat of 162.4 W/m^(2).展开更多
The study aimed to improve the water condensation process in a pyramidal solar still through thermal techniques,focusing on Karbala,Iraq’s hot and dry climate.Various cooling methods-including air and thermoelectric ...The study aimed to improve the water condensation process in a pyramidal solar still through thermal techniques,focusing on Karbala,Iraq’s hot and dry climate.Various cooling methods-including air and thermoelectric cooling with water were integrated and tested in a multi-stage pyramid-shaped solar still to enhance condensation on separate glass surfaces.The system uniquely combines two cooling techniques to address the high thermal load resulting from multiple condensation surfaces.Air cooling(2-8 m/s)and water cooling(105-620 W)were evaluated.Air cooling was applied at speeds of 2,4,6,and 8 m/s with corresponding wattages of 80,120,160,and 200 W.Water cooling with thermoelectric and heat sink methods involved wattages of 105,210,315,and 410 W for each condensation glass,with initial solar radiation intensity measured at 995 W/m^(2)on 24 May 2024.Air cooling increased condensation speed by up to 12%at noon,aided by the dry environment.Water temperature in the basin without cooling reached 65℃,dropping to 53.3℃with a maximum 620 W cooling power consumption.Productivity analysis showed a 48.3%improvement in the morning at an input power of 330 W,which increased to 55%at 620 W.The system achieved a maximum water productivity of 2797 mL/m^(2),with an estimated production cost of 0.078 USD per liter.However,increased energy consumption for cooling reduced overall thermal efficiency due to larger condensation areas in the pyramid solar still requiring more energy,despite enhancing water productivity.展开更多
文摘Maximizing the power capture is an important issue to the turbines that are installed in low wind speed area. In this paper, we focused on the modeling and control of variable speed wind turbine that is composed of two-mass drive train, a Squirrel Cage Induction Generator (SCIG), and voltage source converter control by Space Vector Pulse Width Modulation (SPVWM). To achieve Maximum Power Point Tracking (MPPT), the reference speed to the generator is searched via Extremum Seeking Control (ESC). ESC was designed for wind turbine region II operation based on dither-modulation scheme. ESC is a model-free method that has the ability to increase the captured power in real time under turbulent wind without any requirement for wind measurements. The controller is designed in two loops. In the outer loop, ESC is used to set a desired reference speed to PI controller to regulate the speed of the generator and extract the maximum electrical power. The inner control loop is based on Indirect Field Orientation Control (IFOC) to decouple the currents. Finally, Particle Swarm Optimization (PSO) is used to obtain the optimal PI parameters. Simulation and control of the system have been accomplished using MATLAB/Simulink 2014.
文摘In the face of an escalating global water crisis,countries worldwide grapple with the crippling effects of scarcity,jeopardizing economic progress and hindering societal advancement.Solar energy emerges as a beacon of hope,offering a sustainable and environmentally friendly solution to desalination.Solar distillation technology,harnessing the power of the sun,transforms seawater into freshwater,expanding the availability of this precious resource.Optimizing solar still performance under specific climatic conditions and evaluating different configurations is crucial for practical implementation and widespread adoption of solar energy.In this study,we conducted theoretical investigations on three distinct solar still configurations to evaluate their performance under Baghdad’s climatic conditions.The solar stills analyzed include the passive solar still,themodified solar still coupled with a magnetic field,and themodified solar still coupled with bothmagnetic and electrical fields.The results proved that the evaporation heat transfer coefficient peaked at 14:00,reaching 25.05 W/m^(2).℃for the convention pyramid solar still(CPSS),32.33 W/m^(2).℃for the magnetic pyramid solar still(MPSS),and 40.98 W/m^(2).℃for elecro-magnetic pyramid solar still(EMPSS),highlighting their efficiency in converting solar energy to vapor.However,exergy efficiency remained notably lower,at 1.6%,5.31%,and 7.93%for the three still types,even as energy efficiency reached its maximum of 18.6%at 14:00 with a corresponding peak evaporative heat of 162.4 W/m^(2).
文摘The study aimed to improve the water condensation process in a pyramidal solar still through thermal techniques,focusing on Karbala,Iraq’s hot and dry climate.Various cooling methods-including air and thermoelectric cooling with water were integrated and tested in a multi-stage pyramid-shaped solar still to enhance condensation on separate glass surfaces.The system uniquely combines two cooling techniques to address the high thermal load resulting from multiple condensation surfaces.Air cooling(2-8 m/s)and water cooling(105-620 W)were evaluated.Air cooling was applied at speeds of 2,4,6,and 8 m/s with corresponding wattages of 80,120,160,and 200 W.Water cooling with thermoelectric and heat sink methods involved wattages of 105,210,315,and 410 W for each condensation glass,with initial solar radiation intensity measured at 995 W/m^(2)on 24 May 2024.Air cooling increased condensation speed by up to 12%at noon,aided by the dry environment.Water temperature in the basin without cooling reached 65℃,dropping to 53.3℃with a maximum 620 W cooling power consumption.Productivity analysis showed a 48.3%improvement in the morning at an input power of 330 W,which increased to 55%at 620 W.The system achieved a maximum water productivity of 2797 mL/m^(2),with an estimated production cost of 0.078 USD per liter.However,increased energy consumption for cooling reduced overall thermal efficiency due to larger condensation areas in the pyramid solar still requiring more energy,despite enhancing water productivity.
