Research Of PV Internal Parameters Change Rules In The Process Of PV Aging

With the excessive resource consumption and environment pollution, new energy has received more and more attention. Renewable energy industry, which is represented by PV [photovoltaic] industry, has rapid developed. The fault type of PV mainly includes photovoltaic aging, photovoltaic lobes and hot spot. The study about hot spot problem has now developed to the level of fault location, but the variation of internal parameters when photovoltaic aging happens remains an unsolved mystery.In order to accurately establish photovoltaic cell aging model, the article has researched the photovoltaic cell aging changes of internal parameters, revealed the internal parameters of photovoltaic battery changes with aging process of the photovoltaic battery. This article is based on the photovoltaic cell model and the aging theory. In order to analyze the internal parameter of photovoltaic, we must first identify the parameters by collecting external voltage and current of the circuit, and obtaining the photovoltaic characteristic curves of I-V. After data processing and data filtering, the collected data are used into Self-adaptive Chaos Particle Swarm algorithm for parameter identification. The algorithm has the advantages of rapid optimization and high accuracy. The results of parameter identification in the conditions are the actual value of the internal parameters of photovoltaic cells.Finally, in order to find the variation rule of internal parameters of photovoltaic aging process, more than 150 groups of outdoor experiments have been done under different aging degree and different irradiance and temperature, respectively. Internal parameter identification results are fitted, and then we can get all parameters variation rule when aging degree, irradiance and temperature change. This study is not only a preliminary work for establishing the photovoltaic cell aging model, but also can be applied in practical engineering.