For the carbon-neutral,a multi-carrier renewable energy system(MRES),driven by the wind,solar and geothermal,was considered as an effective solution to mitigate CO2emissions and reduce energy usage in the building sec...For the carbon-neutral,a multi-carrier renewable energy system(MRES),driven by the wind,solar and geothermal,was considered as an effective solution to mitigate CO2emissions and reduce energy usage in the building sector.A proper sizing method was essential for achieving the desired 100%renewable energy system of resources.This paper presented a bi-objective optimization formulation for sizing the MRES using a constrained genetic algorithm(GA)coupled with the loss of power supply probability(LPSP)method to achieve the minimal cost of the system and the reliability of the system to the load real time requirement.An optimization App has been developed in MATLAB environment to offer a user-friendly interface and output the optimized design parameters when given the load demand.A case study of a swimming pool building was used to demonstrate the process of the proposed design method.Compared to the conventional distributed energy system,the MRES is feasible with a lower annual total cost(ATC).Additionally,the ATC decreases as the power supply reliability of the renewable system decreases.There is a decrease of 24%of the annual total cost when the power supply probability is equal to 8%compared to the baseline case with 0%power supply probability.展开更多
Energy flexibility can address the challenges of large scale integration of renewable energy resources and thereby increasing imbalance in the power system. Flexible power system can provide reliable supply, low elect...Energy flexibility can address the challenges of large scale integration of renewable energy resources and thereby increasing imbalance in the power system. Flexible power system can provide reliable supply, low electricity cost and sustainability. Various situations and factors influence the adoption of the flexibility solutions, such as flexible electricity generation, demand-response, and electricity storage. This paper tries to analyze the current energy flexibility solutions and the factors that can influence the energy flexibility adoption. This paper takes Philippines as case study to provide an overview of the current condition of the Philippines＇ power system and discuss the energy flexibility in the Philippines＇ power system. A further discussion and recommendation is conducted in the end of the paper.展开更多
Variations in the behavior of power supplies caused electrical behavior dependence with environmental conditions. by environmental conditions require accurate characterization of the This paper introduces models to he...Variations in the behavior of power supplies caused electrical behavior dependence with environmental conditions. by environmental conditions require accurate characterization of the This paper introduces models to help predict relative humidity （Rtt） and other environmental factors influence on sensitive circuitry in power electronic systems. The resistivity and permittivity of an insulator have been modeled using different water contents i.e. RH, such model also included the mechanical properties of the design. An application example of a high power density, high voltage DC-DC converter is used to verify the results.展开更多
The radar power supplies exhibit a complex electronics. The development of more and more compact systems leads to master the interaction between different parts of the power supply while reducing electronic circuits, ...The radar power supplies exhibit a complex electronics. The development of more and more compact systems leads to master the interaction between different parts of the power supply while reducing electronic circuits, magnetic and thermal couplings from the constitutive circuitry. The consideration of these phenomena is very difficult at the design of the power supply. This paper presents two complementary methods based first on a circuitry model for the quantification of heat sources and secondly on finite element model for heat diffusion. This approach can help a designer in the goal of improving the performances and thermal stability of radar tied to the supply circuit subset.展开更多
A comprehensive performance evaluation of a solar assisted transcritical CO2-based Rankine cycle system is made with exergy analysis method. The actual thermal data taken from the all-day experiment of the system are ...A comprehensive performance evaluation of a solar assisted transcritical CO2-based Rankine cycle system is made with exergy analysis method. The actual thermal data taken from the all-day experiment of the system are utilized to determine energy transfer and the exergy destructions in each component of the system. In addition, a hypothetical carbon dioxide expansion turbine is introduced, then two thermodynamic models for solar transcritical carbon dioxide Rankine cycles with a throttling valve (experiment) and with an expansion turbine have been established with exergy analysis method. The obtained results clearly show that solar collector contributes the largest share to system irreversibility and entropy generation in the all-day working state, and the exergy improvement potential of solar collector is the maximum in the working state. So this component should be the optimization design focus to improve system exergy effectiveness. For the cycle with the turbine, the energy efficiency and the entropy generation are not much higher than the cycle with throttling valve, but the exergy efficiency of the cycle with turbine is twice of the cycle with throttling valve. It provides more guidance when the transcritical CO2-based Rankine system is in a large-scale solar application.展开更多
基金Project(52108101)supported by the National Natural Science Foundation of ChinaProjects(2020GK4057,2021JJ40759)supported by the Hunan Provincial Science and Technology Department,China。
文摘For the carbon-neutral,a multi-carrier renewable energy system(MRES),driven by the wind,solar and geothermal,was considered as an effective solution to mitigate CO2emissions and reduce energy usage in the building sector.A proper sizing method was essential for achieving the desired 100%renewable energy system of resources.This paper presented a bi-objective optimization formulation for sizing the MRES using a constrained genetic algorithm(GA)coupled with the loss of power supply probability(LPSP)method to achieve the minimal cost of the system and the reliability of the system to the load real time requirement.An optimization App has been developed in MATLAB environment to offer a user-friendly interface and output the optimized design parameters when given the load demand.A case study of a swimming pool building was used to demonstrate the process of the proposed design method.Compared to the conventional distributed energy system,the MRES is feasible with a lower annual total cost(ATC).Additionally,the ATC decreases as the power supply reliability of the renewable system decreases.There is a decrease of 24%of the annual total cost when the power supply probability is equal to 8%compared to the baseline case with 0%power supply probability.
文摘Energy flexibility can address the challenges of large scale integration of renewable energy resources and thereby increasing imbalance in the power system. Flexible power system can provide reliable supply, low electricity cost and sustainability. Various situations and factors influence the adoption of the flexibility solutions, such as flexible electricity generation, demand-response, and electricity storage. This paper tries to analyze the current energy flexibility solutions and the factors that can influence the energy flexibility adoption. This paper takes Philippines as case study to provide an overview of the current condition of the Philippines＇ power system and discuss the energy flexibility in the Philippines＇ power system. A further discussion and recommendation is conducted in the end of the paper.
文摘Variations in the behavior of power supplies caused electrical behavior dependence with environmental conditions. by environmental conditions require accurate characterization of the This paper introduces models to help predict relative humidity （Rtt） and other environmental factors influence on sensitive circuitry in power electronic systems. The resistivity and permittivity of an insulator have been modeled using different water contents i.e. RH, such model also included the mechanical properties of the design. An application example of a high power density, high voltage DC-DC converter is used to verify the results.
文摘The radar power supplies exhibit a complex electronics. The development of more and more compact systems leads to master the interaction between different parts of the power supply while reducing electronic circuits, magnetic and thermal couplings from the constitutive circuitry. The consideration of these phenomena is very difficult at the design of the power supply. This paper presents two complementary methods based first on a circuitry model for the quantification of heat sources and secondly on finite element model for heat diffusion. This approach can help a designer in the goal of improving the performances and thermal stability of radar tied to the supply circuit subset.
基金supported by the National Natural Science Foundation of China (Grant No.50976002)
文摘A comprehensive performance evaluation of a solar assisted transcritical CO2-based Rankine cycle system is made with exergy analysis method. The actual thermal data taken from the all-day experiment of the system are utilized to determine energy transfer and the exergy destructions in each component of the system. In addition, a hypothetical carbon dioxide expansion turbine is introduced, then two thermodynamic models for solar transcritical carbon dioxide Rankine cycles with a throttling valve (experiment) and with an expansion turbine have been established with exergy analysis method. The obtained results clearly show that solar collector contributes the largest share to system irreversibility and entropy generation in the all-day working state, and the exergy improvement potential of solar collector is the maximum in the working state. So this component should be the optimization design focus to improve system exergy effectiveness. For the cycle with the turbine, the energy efficiency and the entropy generation are not much higher than the cycle with throttling valve, but the exergy efficiency of the cycle with turbine is twice of the cycle with throttling valve. It provides more guidance when the transcritical CO2-based Rankine system is in a large-scale solar application.
