On-board state of health estimation of Li-Ion batteries packs using incremental capacity analysis with principal components

Abstract

In the past decade state of health (SoH) estimation has become one of the most important aspects in diagnostics of lithium-ion batteries. An accurate on-board monitoring of SoH related parameters allows a correct estimation of actual capacity and power capability of a battery as well as optimistaion of charge/discharge operational mode to prolong a lifetime of a battery. At the same time it still remains a significant challenge regarding practical realisation. Incremental capacity (ICA) and differential voltage (DVA) analysis are purposeful and well investigated methods for recognition and quantification of degradation mechanisms. However, both methods are based on numerical calculation of derivatives and therefore are sensitive to measurement noise. Under real application conditions it makes an automatic recognition of degradation almost impossible. In this paper, a new approach based on application of principal component analysis, is proposed to enhance a diagnostics capability of ICA.