Battery state estimation system, battery control system, battery system, and battery state estimation method

摘要

A battery state estimation system estimates a state of charge of a chargeable battery. A SOCv computing unit calculates a state of charge of the battery using a voltage applied across the battery. A SOCi computing unit integrates a current flowing through the battery to calculate a state of charge of the battery. A SOCw computing unit which performs weighted addition to the state of charge of the battery calculated by the SOCv computing unit and the state of charge of the battery calculated by the SOCi computing unit, wherein when the temperature of the battery is a threshold value or less and the current flowing through the battery is a threshold value or less, the SOCw computing unit sets the specific gravity at the state of charge of the battery calculated by the SOCi computing unit larger than that in other cases upon the weighted addition.

主权项

1. A battery state estimation system comprising:
a temperature measuring unit which measures a temperature of the battery; a current measuring unit which measures a current flowing through the battery; a voltage measuring unit which measures a voltage applied across the battery; a resistance measuring unit which measures an internal resistance of the battery; an SOCv computing unit configured to determine an SOCv value based on a state of charge of a battery using the voltage applied across the battery; an SOCi computing unit configured to determine an SOCi value based on the current flowing through the battery to calculate a state of charge of the battery; a weight computing unit that is configured to: compare the temperature of the battery to a temperature threshold value; compare the current flowing through the battery to a current threshold value; determine a weighting factor (W), based on the internal resistance of the battery and the current flowing through the battery but not the temperature of the battery, when at least one of the following is determined based on the comparisons: the temperature of the battery is greater than a temperature threshold value, or the current flowing through the battery is greater than the current threshold value; determine W, based on the internal resistance of the battery, the current flowing through the battery, and the temperature of the battery, when the temperature of the battery is determined, based on the comparison, to be less than or equal to the temperature threshold value and the current flowing through the battery is determined, based on the comparison, to be less than or equal to the current threshold value, wherein determining W includes:
identifying a value Wgain based on the temperature of the battery and the current flowing through the battery, anddetermining W based on the value Wgain; and a SOCw computing unit that is configured to: calculate a state of charge SOCw value according to Equation 1,
Equation 1: SOCw=W*SOCv+(1−W)*SOCi.