Online impedance spectroscopy estimation of a battery

Important Technical Considerations in Design of Battery Chargers of Electric Vehicles

“…The electrical models are made up of electrical components and are easier for electrical engineers to predict behaviour and parameters of the battery such as capacity, lifetime, state of charge (SOC), and so on [81,83]. Most of the electrical models can be classified into Thevenin-based [81], impedance-based [80][81][82][84][85][86][87], and runtime-based models [81]. They can describe the battery in the long term, the short term, and transients.…”

An Enhanced Lithium-Ion Battery Model for Estimating the State of Charge and Degraded Capacity Using an Optimized Extended Kalman Filter

“…To ensure that the modeled capacity is converging to the actual capacity, a recalibration is needed based on the measured capacity by charging-current integration in stage 4. The measured capacity between the beginning SOC (SOCb) and ending SOC (SOCe) at stage 4 is defined in (11). Eventually, both modeled and measured capacities participate in estimating the current capacity of the battery via a PI-based closed-loop compensator, as given in (12).…”

“…Furthermore, this approach requires knowing both the initial SOC at each operation and the state of health (SOH) to update the current capacity of the battery [10]. Estimating the SOC based on measuring the chemical impedance by means of applying an AC current through the battery at different frequencies is an efficient method that is more precise than both previous methods [11,12]. However, this method is not universal and not easily used in online applications.…”

Online impedance spectroscopy estimation of a dc–dc converter connected battery using a switched capacitor‐based balancing circuit

“…This technique requires additional hardware and there are extra costs involved with the implementation. The authors of [1–4, 6, 8, 13–16] use the power electronics circuitry to generate the EIS excitation signal. The method of introducing a small excitation signal through the dc/dc power electronics is primarily a function of different forms of control.…”

“…The normal operational mode can also be split into different methods used to introduce a low‐frequency signal. These methods include using a variable voltage set point [7] and a variable duty cycle [3, 6, 8, 13–15]. Some initial work has been undertaken to look at using the battery balancing circuit to generate the excitation signal.…”