Lithium iron phosphate battery state estimation method corrected by ampere-hour integral method

The invention discloses a lithium iron phosphate battery state estimation method modified by an ampere-hour integral method, and relates to the field of lithium battery state estimation methods. The charge state of the lithium iron phosphate battery is very difficult to estimate due to the special open-circuit voltage characteristic and voltage and current measurement errors. According to the method, an improved adaptive extended Kalman algorithm and an adaptive unscented Kalman algorithm are adopted to respectively estimate equivalent circuit model parameters and SOC of the lithium iron phosphate battery; and then delimiting a voltage platform area range, setting a scale factor in the voltage platform area, and if an error value is greater than the scale factor, substituting the SOC estimation value of the ampere-hour integral method into the adaptive algorithm to correct the state estimation value, thereby overcoming the defects of the adaptive algorithm, and effectively improving the state estimation preci