INTRODUCTION On the basis of dynamic building simulations within a maximal realistic framework,it may be useful with respect to the overall energy balance to dispense with pursuing a minimal surface/volume ratio of bu...INTRODUCTION On the basis of dynamic building simulations within a maximal realistic framework,it may be useful with respect to the overall energy balance to dispense with pursuing a minimal surface/volume ratio of buildings-thus minimizing heat losses across the building shell-in favor of solar energy use.The specific use of the building(here:office or residential)plays a crucial role.Balancing the energy demand for heating and cooling and a possible photovoltaic yield,a surplus is possible in all cases under investigation.Long,low unobstructed buildings perform best due to large portions of roof area suitable for solar energy use.For tall buildings with less roof area,parts of the facades may be used for solar applications which makes them also perform better than compact designs.If the total energy demand including auxiliary energy for HVAC and especially electricity for the office and residential usages,respectively,is considered,compact cubatures of the size considered here(about 3500 m2)are not capable of providing positive energy balances.Residential usage performs worse than office use.Investigations are performed for the climatic conditions of Berlin,Germany.展开更多
To solve the problem of permanent-shadow shading of photovoltaic buildings,a maximum power point tracking(MPPT)strategy to determine the search range by pre-delimiting area is proposed to improve MPPT efficiency.The s...To solve the problem of permanent-shadow shading of photovoltaic buildings,a maximum power point tracking(MPPT)strategy to determine the search range by pre-delimiting area is proposed to improve MPPT efficiency.The single correspondence between the solar-cell current-voltage(I-V)curve and the illumination conditions was proved by using the single-diode model of photovoltaic cells,thus proving that a change in the illumination conditions corresponds to a unique maximum power point(MPP)search area.According to the approximate relationship between MPP voltage,current and open-circuit voltage and short-circuit current of a photovoltaic module,the voltage region where the MPP is located is determined and the global maximum power point is determined using the power operating triangle strategy in this region.Simulation carried out in MATLAB proves the correctness and feasibility of the theoretical research.Simulation results show that the MPPT strategy proposed in this paper can improve the average efficiency by 1.125%when applied in series as building integrated photovoltaics.展开更多
文摘INTRODUCTION On the basis of dynamic building simulations within a maximal realistic framework,it may be useful with respect to the overall energy balance to dispense with pursuing a minimal surface/volume ratio of buildings-thus minimizing heat losses across the building shell-in favor of solar energy use.The specific use of the building(here:office or residential)plays a crucial role.Balancing the energy demand for heating and cooling and a possible photovoltaic yield,a surplus is possible in all cases under investigation.Long,low unobstructed buildings perform best due to large portions of roof area suitable for solar energy use.For tall buildings with less roof area,parts of the facades may be used for solar applications which makes them also perform better than compact designs.If the total energy demand including auxiliary energy for HVAC and especially electricity for the office and residential usages,respectively,is considered,compact cubatures of the size considered here(about 3500 m2)are not capable of providing positive energy balances.Residential usage performs worse than office use.Investigations are performed for the climatic conditions of Berlin,Germany.
文摘To solve the problem of permanent-shadow shading of photovoltaic buildings,a maximum power point tracking(MPPT)strategy to determine the search range by pre-delimiting area is proposed to improve MPPT efficiency.The single correspondence between the solar-cell current-voltage(I-V)curve and the illumination conditions was proved by using the single-diode model of photovoltaic cells,thus proving that a change in the illumination conditions corresponds to a unique maximum power point(MPP)search area.According to the approximate relationship between MPP voltage,current and open-circuit voltage and short-circuit current of a photovoltaic module,the voltage region where the MPP is located is determined and the global maximum power point is determined using the power operating triangle strategy in this region.Simulation carried out in MATLAB proves the correctness and feasibility of the theoretical research.Simulation results show that the MPPT strategy proposed in this paper can improve the average efficiency by 1.125%when applied in series as building integrated photovoltaics.
