Yokogawa Electric Corporation

Masaru Nakagomi

Satoshi Yoshitake

Soichiro Torai

Masahiro Kazumi

Ryuuta Tanaka

Satoshi Hamano

An estimation method includes: performing, for each different degree of degradation, regression analysis between a first value and a second value, wherein the first value is related to one or more reference feature points on a differential curve of a charging-discharging curve indicating a voltage value with respect to integrated current amount of a reference storage battery, and the second value is at least one of a capacity value of the reference storage battery and an internal resistance value of the reference storage battery; and estimating at least one of a capacity value of a target storage battery and an internal resistance value of the target storage battery, based on a result of the regression analysis and a third value related to one or more target feature points on a differential curve of a charging-discharging curve of the target storage battery.

Estimation method, estimation system, and non-transitory computer-readable recording medium

A secondary battery capacity measuring system that estimates maximum capacities of other cells using characteristics of a deteriorated cell even when a charging process in the deteriorated cell having a smaller maximum capacity than the other cells in cells constituting a battery module ends and data for measuring the maximum capacities of the other cells cannot be acquired is provided.

Secondary battery capacity measuring system and secondary battery capacity measuring method

A secondary battery capacity measurement system includes a data convertor, an SOC computer, and a maximum capacity computer. The data convertor determines a partial derivative characteristic curve of a capacity-to-voltage derivative over voltage, the partial derivative characteristic curve indicating a characteristic of a capacity-to-voltage derivative, from a set of historical data of time-sequentially-measured values of voltage and current. The SOC computer computes a difference between the partial derivative characteristic curve and a reference derivative curve indicating a reference characteristic of the capacity-to-voltage derivative, and fits the partial derivative characteristic curve to the reference derivative curve by reducing the difference to estimate an SOC. The maximum capacity computer estimates a maximum value of capacity, from the partial derivative characteristic curve and the reference derivative curve. The reference derivative curve is given by a complex of first and second characteristic derivative curves respectively derived from positive and negative electrode materials.

Secondary battery capacity measurement system and secondary battery capacity measurement method

A secondary-battery maximum-capacity measuring apparatus, includes: a current dependency processing unit configured to convert an inter-terminal voltage and an open cell voltage of a secondary battery into values without depending on a load current based on an amount of change in relative value of a voltage during a time period when a constant current is drawn from the secondary battery; and an error calculation unit configured to compute errors of the inter-terminal voltage and the open cell voltage of the secondary battery, the inter-terminal voltage and the open cell voltage being converted by the current dependency processing unit.

Growing community of inventors

Tokyo, Japan

Masaru Nakagomi