Patent ID: 8975897
Filing Date: 2015-03-10
Classification: G01R

Abstract:
1. A state-of-charge estimating apparatus connected to a power storage apparatus, in which a plurality of batteries are connected, and configured to estimate a state of charge indicating a residual capacity of the power storage apparatus, the state-of-charge estimating apparatus comprising: a first arithmetic unit configured to calculate, as a first state-of-charge estimation value, a present value of a state-of-charge estimation value calculated based on a battery capacity, a last value of the state-of-charge estimation value, and an electric current flowing in and out between a current control apparatus, which controls charge and discharge amounts of the power storage apparatus, and the power storage apparatus; a second arithmetic unit configured to calculate, during constant current control for charging the power storage apparatus with a constant current, as a present value of a second state-of-charge estimation value, a state-of-charge estimation value calculated based on an equivalent circuit model of the battery and a voltage of the battery and, on the other hand, calculate, during constant voltage control for charging the power storage apparatus with a constant voltage, as the second state-of-charge estimation value, a present value of a state-of-charge estimation value calculated taking into account a resistance change of the battery based on the equivalent circuit model of the battery and the voltage of the battery; and a correction arithmetic unit configured to periodically correct the first state-of-charge estimation value with the second state-of-charge estimation value.