Battery aging due to 100 Hz current ripple of power converters

Lithium ion batteries (LIBs) represent one of the most important and used storage systems in different applications. In particular, the issue of the intermittence in power generation of renewable energy sources make it necessary their implementation in such plants. It is very important to take into account the aging phenomena of LIBs to optimize their usage and extend their lifetime. The aging is usually decomposed into calendar aging and cycle aging. In general, the factors that affect it are the temperature, the state of charge, the voltage limits, and the current rate. Several works analysed also the effect of the current ripple on the battery aging. Nevertheless, a rigorous analysis of the effect of the current frequency seems to be missing. Indeed, almost all the aging analyses relating current ripple do not take into account the higher temperatures due to the current ripple losses. Therefore, the effects of increased temperature and current ripple are never separated. Moreover, different frequency components in the same current ripple may lead to different aging. In this paper, a method to separate the temperature by the current frequency effect is proposed and the analysis of the aging LIBs due to the 100 Hz current harmonic is carried out.