Characteristics Evaluation of 14 Battery Equivalent Circuit Models

In this study, we formulate and implement 14 widely used battery-equivalent circuit models (ECMs) in a MATLAB/Simulink environment and extract the parameters using the hybrid pulse power characterization (HPPC) test results based on the parameter estimator app working on the curve-fitting method. Using the extracted parameter values, which are either state of charge-dependent sixth-degree polynomials or constants, we perform an error fluctuation deviation analysis on two different real flight test results by loading 0 kg and 10 kg payloads on a hexacopter unmanned aerial vehicle for the ECM characteristic evaluation. According to the error characteristic analysis, the Liu ECM resulted in the lowest root mean square (RMS) (0.0376 V), standard deviation (SD) (0.0343 V), and maximum errors (0.6159 V) for the HPPC test, the Rint ECM resulted in the lowest RMS (0.0702 V) and maximum errors (0.6844 V) for the real flight test carrying a 0 kg payload, and the Shepherd ECM resulted in the lowest RMS (0.0875 V) and SD errors (0.0872 V) for the real flight test carrying a 10 kg payload. In conclusion, we recommend the Shepherd ECM with constant parameters owing to its fast parameter optimization convergence time and flexibility to the dynamic discharging load with a smaller error.