The invention belongs to the technical field of
energy storage, and relates to a
lithium battery energy storage
system nonlinear capacity recession trajectory prediction method, which comprises the following steps: collecting
discharge data of a first cycle period and an mth cycle period of a
lithium battery, and extracting a
voltage-capacity curve of the mth cycle period from the
discharge data; the method comprises the following steps: extracting a
voltage-capacity curve of an mth cycle period, extracting a capacity increment curve and a capacity difference curve of the mth cycle period on the basis of the
voltage-capacity curve, respectively constructing GASF (Gramian Angle Summation Field) graphs on the basis of the voltage-capacity curve, the capacity increment curve and the capacity difference curve, and combining to form a multi-channel format as the input of a prediction model. The method comprises the following steps: firstly, acquiring a degradation track, outputting a degradation track key node on the basis of a prediction model, then integrating the predicted degradation track key node with battery
state of health (SOH) information of an mth cycle period, realizing the reconstruction of a capacity degradation track through a three-time
Hermite Interpolation Polynomial (PCHIP), realizing
data information mining through the collection of early data, and finally realizing the reconstruction of the capacity degradation track. Therefore, the model obtains sufficient degradation information, precise trajectory prediction is realized, the
degradation process information of the
lithium battery is mastered in the early stage, and time margin is provided for operation and maintenance of an
energy storage system.