INTERNAL RESISTANCE ESTIMATOR FOR SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide an internal resistance estimator for a secondary battery to accurately estimate an internal resistance value even in a state where it is difficult to perform estimating calculation by means of an adaptive digital filter as in constant current discharge or large current discharge. SOLUTION: This internal resistance estimator is structured so as to choose between a first internal resistance value estimated by means of the adaptive digital filter and a second internal resistance value found from a second charging rate estimation value based on current integration, etc. in accordance with the state of current. In a state where charging rate estimation by means of the adaptive digital filter is difficult, the second charging rate estimation value based on current integration, etc. is chosen. In the other cases, a first charging rate estimation value (and the first internal resistance value) by means of the adaptive digital filter are chosen. In cases where the second internal resistance value is estimated from the second charging rate estimation value, stored values T1_ADF(k) and T2_ADF(k) of battery parameter estimation values by means of the digital filter just before choosing a second charging rate are held, and these are used for operating the second internal resistance value K_ITG(k). COPYRIGHT: (C)2007,JPO&INPIT