The aim of this paper is to present graphically the behaviour of a simulation model to the varying parameters and to establish the suitability of this representation as a valid tool for the analysis of the same parame...The aim of this paper is to present graphically the behaviour of a simulation model to the varying parameters and to establish the suitability of this representation as a valid tool for the analysis of the same parameters. In this paper, we define parameter combinatorial diagram as the joint graphical representation of all box plots related to the adjustment between real and simulated data, by setting and/or changing the parameters of the simulation model. To do this, we start with a box plot representing the values of an objective adjustment function, achieving these results when varying all the parameters of the simulation model, Then we draw the box plot when setting all the parameters of the model, for example, using the median or average. Later, we get all the box plots when carrying out simulations combining fixed or variable values of the model parameters. Finally, all box plots obtained are represented neatly in a single graph. It is intended that the new parameter combinatorial diagram is used to examine and analyze simulation models useful in practice. This paper presents combinatorial diagrams of different examples of application as in the case of hydrologic models of one, two, three, and five parameters.展开更多
In this communication we start both from a trirectangular trihedral defined by the three coordinate planes and a fourth plane, called the chart or projection, which contains the vertex of the trihedral above. Later we...In this communication we start both from a trirectangular trihedral defined by the three coordinate planes and a fourth plane, called the chart or projection, which contains the vertex of the trihedral above. Later we define the main related views or trihedral views as those produced by the tilt of the three coordinate planes to the outside of their trihedral on the chart plane. For each projection plane there are some unique main related views, regardless of the projection direction. In turn, from the trihedral views we can obtain the axonometric perspective from which they come. These properties can simplify some graphic constructions of the axonometric system, for example, determine the projections of the axes from the main related views or determine the axonometric scales from the axes. It is considered that this new definition of related views allows a simplification as to the understanding of the representation systems and it is intended to be suitable for teaching purposes and programming.展开更多
The concept of employing thermoelectric generators(TEGs)to recover energy from waste heat has gained popularity,with applications that range from milliwatt to kilowatt levels of output power.In this study,a hybrid pho...The concept of employing thermoelectric generators(TEGs)to recover energy from waste heat has gained popularity,with applications that range from milliwatt to kilowatt levels of output power.In this study,a hybrid photovoltaic panel and thermoelectric generator(HPVTEG)system consisting of an integrated heat exchanger,a commercial polycrystalline silicon photovoltaic(PV)panel and a commercial bismuth telluride TEG was proposed.Here,TE components can be used to cool PV modules,increasing their output power via the Seebeck effect.The main finding is that the hybrid system has a reduced average temperature of 16.01°C.The average power of the stand-alone PV panel is 28.06 W,but that of the HPVTEG system is 32.76 W,which is an increase of 4.7 W.The conversion efficiency and power of the hybrid system increased by 16.7%and 16.4%,respectively,compared with a stand-alone PV panel.The HPVTEG system achieved an average exergy efficiency of 12.79%compared with 10.98%for a stand-alone PV panel.According to the calculation results,the levelized cost of energy(LCOE)of the stand-alone PV panel can range from 0.06741 to 0.10251 US$/kWh depending on how many days it is in operation,while the LCOE of the HPVTEG system can range from 0.06681 to 0.10160 US$/kWh.展开更多
The outcome of this paper is to suggest an efficient energy-management strategy(EMS)for a direct-current(DC)microgrid(MG).The typical MG is composed of two renewable energy sources[photovoltaic(PV)systems and fuel cel...The outcome of this paper is to suggest an efficient energy-management strategy(EMS)for a direct-current(DC)microgrid(MG).The typical MG is composed of two renewable energy sources[photovoltaic(PV)systems and fuel cells(FCs)]and two energy-storage elements(lithium-ion battery and supercapacitor).An EMS was proposed to ensure optimal bus voltage with a power-sharing arrangement between the load and the sources.As a result,in the suggested DC MG,non-linear flatness control theory was used instead of the traditional proportional-integral control approach.The suggested EMS is intended to supply high power quality to the load under varying load conditions with fluctuating solar irradiation while considering the FC status.To validate and prove the effectiveness of the proposed EMS,a MATLAB®environment was used.In addition,the output power of the PV system was maximized using the particle swarm optimization algorithm as a maximum power point tracking(MPPT)technique to track the MPP of the 3000-W PV system under different irradiance conditions.The results show that the suggested EMS delivers a stable and smooth DC bus voltage with minimum overshoot value(0.1%)and improved ripple content(0.1%).As a result,the performance of the DC MG was enhanced by employing the flatness control theory,which provides higher power quality by stabilizing the bus voltage.展开更多
文摘The aim of this paper is to present graphically the behaviour of a simulation model to the varying parameters and to establish the suitability of this representation as a valid tool for the analysis of the same parameters. In this paper, we define parameter combinatorial diagram as the joint graphical representation of all box plots related to the adjustment between real and simulated data, by setting and/or changing the parameters of the simulation model. To do this, we start with a box plot representing the values of an objective adjustment function, achieving these results when varying all the parameters of the simulation model, Then we draw the box plot when setting all the parameters of the model, for example, using the median or average. Later, we get all the box plots when carrying out simulations combining fixed or variable values of the model parameters. Finally, all box plots obtained are represented neatly in a single graph. It is intended that the new parameter combinatorial diagram is used to examine and analyze simulation models useful in practice. This paper presents combinatorial diagrams of different examples of application as in the case of hydrologic models of one, two, three, and five parameters.
文摘In this communication we start both from a trirectangular trihedral defined by the three coordinate planes and a fourth plane, called the chart or projection, which contains the vertex of the trihedral above. Later we define the main related views or trihedral views as those produced by the tilt of the three coordinate planes to the outside of their trihedral on the chart plane. For each projection plane there are some unique main related views, regardless of the projection direction. In turn, from the trihedral views we can obtain the axonometric perspective from which they come. These properties can simplify some graphic constructions of the axonometric system, for example, determine the projections of the axes from the main related views or determine the axonometric scales from the axes. It is considered that this new definition of related views allows a simplification as to the understanding of the representation systems and it is intended to be suitable for teaching purposes and programming.
基金the Ministry of Science and Higher Education of the Russian Federation(Ural Federal University Program of Development within the Priority-2030 Program)is gratefully acknowledged(grant number FEUZ-2022-0031).
文摘The concept of employing thermoelectric generators(TEGs)to recover energy from waste heat has gained popularity,with applications that range from milliwatt to kilowatt levels of output power.In this study,a hybrid photovoltaic panel and thermoelectric generator(HPVTEG)system consisting of an integrated heat exchanger,a commercial polycrystalline silicon photovoltaic(PV)panel and a commercial bismuth telluride TEG was proposed.Here,TE components can be used to cool PV modules,increasing their output power via the Seebeck effect.The main finding is that the hybrid system has a reduced average temperature of 16.01°C.The average power of the stand-alone PV panel is 28.06 W,but that of the HPVTEG system is 32.76 W,which is an increase of 4.7 W.The conversion efficiency and power of the hybrid system increased by 16.7%and 16.4%,respectively,compared with a stand-alone PV panel.The HPVTEG system achieved an average exergy efficiency of 12.79%compared with 10.98%for a stand-alone PV panel.According to the calculation results,the levelized cost of energy(LCOE)of the stand-alone PV panel can range from 0.06741 to 0.10251 US$/kWh depending on how many days it is in operation,while the LCOE of the HPVTEG system can range from 0.06681 to 0.10160 US$/kWh.
文摘The outcome of this paper is to suggest an efficient energy-management strategy(EMS)for a direct-current(DC)microgrid(MG).The typical MG is composed of two renewable energy sources[photovoltaic(PV)systems and fuel cells(FCs)]and two energy-storage elements(lithium-ion battery and supercapacitor).An EMS was proposed to ensure optimal bus voltage with a power-sharing arrangement between the load and the sources.As a result,in the suggested DC MG,non-linear flatness control theory was used instead of the traditional proportional-integral control approach.The suggested EMS is intended to supply high power quality to the load under varying load conditions with fluctuating solar irradiation while considering the FC status.To validate and prove the effectiveness of the proposed EMS,a MATLAB®environment was used.In addition,the output power of the PV system was maximized using the particle swarm optimization algorithm as a maximum power point tracking(MPPT)technique to track the MPP of the 3000-W PV system under different irradiance conditions.The results show that the suggested EMS delivers a stable and smooth DC bus voltage with minimum overshoot value(0.1%)and improved ripple content(0.1%).As a result,the performance of the DC MG was enhanced by employing the flatness control theory,which provides higher power quality by stabilizing the bus voltage.
