This application relates to a method and
system for dynamic calibration of the
state of charge (SOC) of
lithium batteries for electric tricycles. The method includes: determining whether the current operating conditions meet the triggering conditions for a dynamic calibration
event based on the total
voltage, current, and temperature of the
lithium battery, and the speed,
motor power, and load status of the electric tricycle; when any dynamic calibration event is triggered, identifying the ohmic
internal resistance and polarization
internal resistance of the
lithium battery using a parameter identification
algorithm, calculating the virtual open-circuit
voltage using a compensation calculation formula, querying a preset SOC table based on the virtual open-circuit
voltage and temperature to obtain a reference SOC value, estimating the predicted SOC value using the
ampere-hour integration method, and fusing the reference SOC value and the predicted SOC value using a
Kalman filter algorithm to obtain the calibrated SOC value. This solves the problems of large errors, poor environmental adaptability, and inability to address SOC drift during dynamic operation in traditional battery SOC calibration methods, significantly improving the SOC
estimation accuracy throughout the entire lifespan.