Abstract:

In this work, an electrical equivalent circuit (ECM) models have been used to simulate INR18650-20R lithium-ion battery response at 0oC, 25oC, and 45oC, respectively. The ECM model parameters are estimated using incremental open-circuit voltage (OCV) profile and Trust-Region Reflective Non-Linear Least Squares algorithm. The estimated parameters of the ECM model experimentally validated using independent dynamic current profiles including Dynamic Stress Test (DST), Federal urban driving schedule (FUDS), Beijing Dynamic Stress test (BJDST), and US06 at 0oC, 25oC, and 45oC, respectively. For model-based online SOC estimation, coulomb-counting-based algorithms are used. The investigated ECM model with three parallel RC branches has accuracy of less than 1.8 percent and appears to be ideal for capturing the nonlinear dynamics of lithium-ion batteries for EV applications. It has been verified that the proposed ECM model produces substantially fewer errors than previously reported models.