An Accurate Time Constant Parameter Determination Method for the Varying Condition Equivalent Circuit Model of Lithium Batteries

Abstract

An accurate estimation of the state of charge for lithium battery depends on an accurate identification of the battery model parameters. In order to identify the polarization resistance and polarization capacitance in a Thevenin equivalent circuit model of lithium battery, the discharge and shelved states of a Thevenin circuit model were analyzed in this paper, together with the basic reasons for the difference in the resistance capacitance time constant and the accurate characterization of the resistance capacitance time constant in detail. The exact mathematical expression of the working characteristics of the circuit in two states were deduced thereafter. Moreover, based on the data of various working conditions, the parameters of the Thevenin circuit model through hybrid pulse power characterization experiment was identified, the simulation model was built, and a performance analysis was carried out. The experiments showed that the accuracy of the Thevenin circuit model can become 99.14% higher under dynamic test conditions and the new identification method that is based on the resistance capacitance time constant. This verifies that this method is highly accurate in the parameter identification of a lithium battery model.

Autonomous Drone Racing: A Survey

“…50-100 C) [41], [42]. Graybox battery models for the voltage that are based on a one-time-constant (OTC) equivalent circuit [43], [44] are much more suitable for drone racing tasks as shown in [4], because they are applicable to the extremely high loads experienced during a racing scenario. In combination with either a polynomial or a constant-efficiency motor model such OTC models can be used to accurately simulate the battery voltage during agile flight [4].…”

Range, Endurance, and Optimal Speed Estimates for Multicopters

“…A review of the common OTC and TTC models is presented in [30]. The OTC model is widely used because of its well-established accuracy [31]. A TTC model only shows improved precision in cases where the battery dynamics need to be accurately captured at very short timescales [32].…”

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“…The battery voltage during the relaxation period Ub(t) while charging/discharging can be fitted to the exponential function form expressed as [10][11] [12]:…”

“…After determining P0, P1, P2, k1, and k2 experimentally, other model parameters could be determined in additional to (4), (5) as follows [10][11] [12]:…”