The equivalent circuit battery model parameter sensitivity analysis for lithium‐ion batteries by Monte Carlo simulation

Abstract

To enhance the estimation accuracy of battery's state of charge, it is imperative to estimate the battery model parameter. To reduce the calculation efforts, the number of the battery model parameter to be estimated should be less while ensuring the state of charge estimation accuracy. Especially in engineering applications, the calculating ability is usually limited. So, it needs to choose the critical battery model parameter to be estimated. This paper's contributions are as follows: The global sensitivity analysis of the battery model parameter is achieved by the Monte Carlo simulation method. The results show that the open circuit voltage and the ohmic resistance are the high sensitivity parameters. Guided by the results of parameter sensitivity analysis, a dual extended Kalman filters method is utilized to achieve online battery model parameter estimation. The experiments prove that the state of charge estimation accuracy is improved by the online parameter estimation. Estimating high sensitivity parameters can reduce running time. And the SOC estimation accuracy can be guaranteed.

A novel interval‐based approach for quantifying practical parameter identifiability of a lithium‐ion battery model

“…As can be seen from the S i values, V oc and R 0 are the two, which have the best identifiability among all the six parameters, establishing sufficient confidence for us to use the estimates of these two parameters in battery diagnostic and control applications. This is also discovered by Guo et al through a global sensitivity analysis of second order ECM parameters . Table further shows that the identifiability of these two parameters tends to be much better in the dynamic operating conditions.…”

“…This is also discovered by Guo et al through a global sensitivity analysis of second order ECM parameters. 22 Table 1 further shows that the identifiability of these two parameters tends to be much better in the dynamic operating conditions. On the other hand, it can be observed that the true value of V oc falls within its estimated CIs in both operating cycles.…”

“…Several methods exist for assessing the practical identifiability of battery parameters. As sensitive parameters tend to have stronger identifiability, traditional sensitivity analysis is usually performed to investigate the practical identifiability of various parameters in an electrochemical model or an ECM . The parameter identifiability for series and parallel battery strings with lumped measurements is analyzed via linear and nonlinear observability tests.…”

“…As sensitive parameters tend to have stronger identifiability, traditional sensitivity analysis is usually performed to investigate the practical identifiability of various parameters in an electrochemical model 20 or an ECM. 21,22 The parameter identifiability for series and parallel battery strings with lumped measurements is analyzed via linear and nonlinear observability tests. It is shown in the tests that model parameters of cells in parallel connection can be determined by using only one voltage and one current sensor.…”

Optimized fast charging protocol for cylindrical lithium‐ion battery based on constant incremental capacity algorithm

“…Based on the anode potential results and engineering experience, the lithium‐ion battery could accept large current at low SOC, 3,18 so the constant dQ/dV could be combined with a large constant current (CC) charge at low SOC to shorten the charging time, as shown in Figure 2B. Since every dQ/dV step could be a constant voltage configuration, the current shows a decreased shape for each step, which could be explained by the first‐ or second‐order model of battery 31 . The inflection point of the current is always around 40% SOC regardless of the value of dQ/dV and the initial current, so we suspect that it is related to the battery characteristics, and the constant current stage should not exceed SOC at inflection point.…”