Key words: photovoltaic bracket, numerical simulation, overall stability, fixed, failure mode. 摘要： 为研究固定式光伏支架在风荷载作用下的受力性能及破坏模式,设计并制作
In Belgrade, the annual power gains of PV systems adjusted at yearly, seasonal and monthly optimum tilt angles are 5.98%, 13.55% and 15.42%, respectively, compared to PV panels fixed at the current roof angle .
These studies revealed that coupling more atmospheric factors can achieve better performance in estimating the optimum PV tilt angles. However, the simulation results were obtained by maximizing the amount of incident solar radiation on PV panel surface, without considering the actual photoelectric conversion process and PV system losses.
Cheng et al. found that more than 98% of south-faced PV systems in 14 countries achieved the optimal performance at a tilt angle equal to the latitude. In North America, the optimum tilt angle is slightly less than the latitude [16, 17]. Some studies suggest that more complex models are necessary for world estimates of the optimum tilt angle.
The optimum tilt angle at the same location changes periodically (Fig. 7) due to the Earth revolution around sun. In summer, when the sun shines more directly on the northern hemisphere, the tilt angle is generally small; winter is the opposite. Adjusting the tilt angle of PV panels according to the season helps capturing more energy.
Hourly power generation of solar PVs at different tilt angles is modelled by PVLIB model, which can take into account the actual photoelectric conversion process and PV system losses caused by various environmental factors.
At more than half of the stations in China, optimally tilted PVs can achieve annual yield gain of more than 30 kWh (the maximum reaches up to 100 kWh), and an additional gain of 10–30 kWh is available if the tilt angle is quarterly adjusted.
