Panasonic Intellectual Property Management Co., Ltd.

Tohru Watanabe

Shinya Nishikawa

Takashi Iida

Kazufumi Nishikawa

Changhui Yang

Yusuke Itakura

Tadao Kimura

Yohei Ishii

Masaaki Takegata

Makoto Hashimoto

A voltage of a battery cell is measured, and a current flowing through the battery cell is measured. An open circuit voltage (OCV) of the battery cell is estimated based on the measured voltage, the measured current, and an equivalent circuit model based on electrochemistry of the battery cell. At least one of a positive electrode and negative electrode of the battery cell is a mixed electrode containing a plurality of materials. The equivalent circuit model is a model including a diffusion resistance component for each of the plurality of materials for use in the positive electrode and the negative electrode.

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

A controller executes an equalization process of equalizing capacities of a plurality of cells, and a cell abnormality determination process of, of detected voltages of the plurality of cells, calculating a voltage difference between a representative voltage based on the detected voltage of at least one cell to be compared and the detected voltage of one cell to be detected at a first time and a second time, and when a difference between the two voltage differences is greater than or equal to a threshold value, determining that the cell to be detected is abnormal. In the case of executing the cell abnormality determination process during the equalization process, the controller provides the detected voltage of a target cell to be subjected to the equalization process with a compensation value corresponding to a voltage change based on energy transfer in the target cell due to the equalization process between the first time and the second time, and calculates the voltage difference at the second time.

Management device and power supply system

Provided is a controller configured: to calculate, among voltages detected from a plurality of cells, a voltage difference between the voltage detected from one cell of the plurality of cells, the one cell to be detected, and a representative voltage at each of a first time and a second time, the representative voltage based on the voltage detected from at least one cell of the plurality of cells, the at least one cell to be compared; and when a discrepancy between the voltage difference at the first time and the voltage difference at the second time is equal to or more than a threshold, to determine that an abnormality has occurred in the one cell to be detected. The controller refers to a state-of-charge versus open-circuit-voltage (SOC-OCV) curve of the one cell to be detected in accordance with a state-of-health (SOH) of the one cell to be detected, so as to estimate an SOC as initial capacitance reference of the one cell to be detected in correspondence to the voltage detected from the one cell to be detected. The controller introduces a linear function using an SOC as initial capacitance reference as an input variable, using an OCV as an output variable, and having a predetermined inclination, and applies the SOC as initial capacitance reference of the one cell to be detected that the controller has estimated to the linear function, so as to derive an OCV. Then, in place of the voltage detected from the one cell to be detected, the controller uses the OCV that the controller has derived, so as to calculate the voltage difference at the first time and the voltage difference at the second time.

A voltage of a battery cell is measured, and a current flowing through the battery cell is measured. An open circuit voltage (OCV) of the battery cell is estimated based on the measured voltage, the measured current, and an equivalent circuit model based on electrochemistry of the battery cell, and a state of charge (SOC) of the battery cell is estimated based on the estimated OCV, SOC-OCV characteristics on a charge side of the battery cell, and SOC-OCV characteristics on a discharge side of the battery cell. At least one of a positive electrode and negative electrode of the battery cell is a mixed electrode containing a plurality of materials. Estimated is a current flowing through a material in which capacity-OCV characteristics are different between the charge side and the discharge side, the material being included in the plurality of materials contained in the mixed electrode, and a ratio between the SOC-OCV characteristics on the charge side and the SOC-OCV characteristics on the discharge side is determined based on the current.

In a vehicle power supply system mounted on an electric vehicle, a vehicle controller switches a discharge power limit to a motor during travel of the electric vehicle according to degradation information of a battery module to which a plurality of cells are connected, the degradation information being calculated in advance before the travel of the electric vehicle. For example, the vehicle controller switches a limit of a maximum acceleration and/or maximum speed of the electric vehicle as the switching of the discharge power limit.

Vehicle power supply system and vehicle dispatch system

A voltage measurer measures a voltage of a battery cell. A controller controls charging-discharging of the battery cell. The controller performs control to apply a reverse current for canceling a polarization voltage of the battery cell through the battery cell after the completion of charging-discharging of the battery cell. For example, after the charging-discharging of the battery cell completes, the controller sets a current command value, in a power converter, that instructs flow of a reverse current of a preset value for a preset time.

Battery system and battery management device for cancelling polarization voltage by applying a reverse current

A managing device calculates a whole state of power (SOP) that is an SOP of a whole of the plurality of power storage blocks based on SOPs of the respective power storage blocks and currents flowing through the respective power storage blocks, and sets an upper limit value of power or a current for at least one of charging and discharging by a power converter, based on the whole SOP thus calculated. The managing device estimates a current flowing through each of the power storage blocks from a voltage and an internal resistances of each of the power storage blocks before the power converter starts power conversion.

Electricity storage system and management device

In a power storage system, a management device calculates a state of power (SOP) of a whole of a plurality of power storage blocks connected in parallel based on an SOP of each of the plurality of power storage blocks to specify the calculated SOP of the whole for an upper limit level of power or current for at least one of charging and discharging controlled by a power converter. When at least one of a plurality of switches is turned off to disconnect at least one () of the plurality of power storage blocks, the management device calculates an SOP of a whole of the remaining power storage blocks based on a deviation in current between each of the remaining power storage blocks to determine an upper limit level of power or current flowing into the power converter.

Power storage system having a plurality of power storage blocks interconnected in parallel and control device

In a power storage system, a management device calculates a state of power (SOP) of a whole of a plurality of power storage blocks connected in parallel based on an SOP of each of the plurality of power storage blocks. At least one of the plurality of power storage blocks is disconnected from the power storage system, and when at least one switch is turned on to return at least one disconnected power storage block to the power storage system having the parallel-connected power storage blocks, the management device calculates an SOP of a whole of the power storage blocks after a return of the at least one power storage block based on a deviation in current between each of the power storage blocks including the at least one returned power storage block to determine an upper limit level of power or current flowing into a power converter.

Growing community of inventors

Gifu, Japan

Tohru Watanabe