A Novel SOC Estimation Method for Lithium Ion Battery Based On Improved Adaptive PI Observer

The study of lithium ion battery is paramount in electric power systems such as the aerospace, electrical vehicle and electrical propulsion system. State of charge estimation accuracy and robustness is significant for good performance and long life of battery. To further increase the accuracy for the estimation of state of charge, an improved adaptive proportional integral observer is proposed. Real time update of parameters of the battery are acquired according to state of charge and error feedback. The battery model is deliberated and the establishment of improved adaptive Proportional integral observer (PIO) is detailed in this work. First order resistance capacitance model is designed in Matlab/Simulink in order to verify the algorithm. The error is minimized by reducing the operations carried out after data acquisition to convert data into information. The estimation process is highly accurate, stable and reliable as compared with conventional adaptive PI observer with estimation accuracy of 99.4%. The estimation algorithm proves to be a great aid for power supply applications of lithium ion battery.