دانلود رایگان مقاله انگلیسی اندازه گیری بهینه اینورتر برای به حداکثر رساندن توان انرژی در سیستم های پیشرفته فتوولتائیک - الزویر 2018

ABSTRACT

The sizing of the inverter in comparison to the rated capacity of the photovoltaic generator is investigated for high-concentrator photovoltaic (HCPV) systems. An HCPV module of typical characteristics is modelled and parameterized, taking into account direct normal irradiance (DNI), ambient temperature, air mass and aerosol optical depth as atmospheric inputs, while the DC losses of the HCPV generator are allowed to vary in the ranges reported in the literature. A set of 80 commercial inverters are analysed to obtain the typical efficiency curves of state-of-the-art low-, medium-, and high-efficiency inverters. Four locations worldwide with high annual DNI levels and different average values of the weather variables influencing HCPV performance are studied. Results show that the inverter can be sized between 84% and 112% of the rated capacity of the HCPV generator at Concentrator Standard Test Conditions depending on the scenario considered for maximizing the final energy yield of the system. The proposed methodology uses analytical equations, all the model parameters are provided and justified and atmospheric inputs are obtained from meteorological databases in order to make the application easy regarding its use in other locations where the climate data is available.

Conclusions

The optimum SR that maximizes the final Yf has been studied for the state-of-the-art technology of HCPV generators and grid-connected inverters. Specifically, a typical HCPV module, three representative types of inverters (low-, medium- and high-efficiency), four locations with high annual DNI levels but different average values of the atmospheric parameters influencing HCPV system performance and variable DC losses of the HCPV generator have been considered in the analysis. The main results of the study can be summarized as follows:

– The optimum SR varies between 0.84 and 1.12.

– The optimum SR increases as the annual direct normal irradiation of the site increases.

– The optimum SR increases as the inverter efficiency decreases.

– The system PR remains almost in its maximum value for a wide range of SR values.

Therefore, from a practical point of view and considering locations with a high annual DNI level, designers can choose SR values between 80% and 150% without compromising the final energy yield of the system.

– The threshold SR that provides 1% less PR than the maximum PR varies between 0.60 and 0.78.

– The optimum SR decreases approximately 0.97% each 1% of increase of the HCPV generator DC losses.