Battery control device and vehicle system

Patent metadata

Field	Value
Publication number	US-2018050681-A1
Application number	US-201615555171-A
Country	US
Kind code	A1
Filing date	Feb 26, 2016
Priority date	Mar 2, 2015
Publication date	Feb 22, 2018
Grant date	—

Abstract

A device for controlling current for charging/discharging a battery with a high accuracy includes a time-point setting unit which calculates a voltage difference by subtracting a calculated open-circuit voltage from a measured closed-circuit voltage, and sets first and second time points, at which an absolute value of the voltage difference becomes equal to or less than a predetermined value and an absolute value of a difference in the open-circuit voltage becomes equal to or less than a predetermined value. The control device further includes a current correction amount calculation unit to obtain the current integral amount, calculate the current error in a detection signal and set the current error as the current correction amount on the basis of the current integral amount and the time from the first time point to the second time point. The current correction unit corrects the detection signal using the current correction amount.

First claim

1 . A battery control device, comprising:
a current detection unit that detects a current flowing through a secondary battery; a closed-circuit voltage detection unit that detects an inter-terminal voltage of the secondary battery to acquire a closed-circuit voltage; an open-circuit voltage calculation unit that performs calculation on the basis of the closed-circuit voltage to acquire an open-circuit voltage; a time-point setting unit that calculates each voltage difference obtained by subtracting the open-circuit voltage from the closed-circuit voltage, and sets a first time point and a second time point at which an absolute value of the voltage difference is equal to or less than a predetermined value and an absolute value of a difference of the open-circuit voltage becomes equal to or less than a predetermined value; a current integral amount calculation unit that obtains a current integral amount, the current integral amount being a time integral amount of a current flowing through the secondary battery between the first time point and the second time point; a current correction amount calculation unit that calculates a current error contained in a detection signal output from the current detection unit on the basis of the current integral amount and a time from the first time point to the second time point, and sets the current error as a current correction amount; and a current correction unit that performs correction on the detection signal using the current correction amount.

2 . A battery control device, comprising:
a current detection unit that detects a current flowing through a secondary battery; a closed-circuit voltage detection unit that detects an inter-terminal voltage of the secondary battery to acquire a closed-circuit voltage; an open-circuit voltage calculation unit that performs calculation on the basis of the closed-circuit voltage to acquire an open-circuit voltage; a time-point setting unit that calculates each voltage difference obtained by subtracting the open-circuit voltage from the closed-circuit voltage, and sets a first time point and a second time point at which an absolute value of the voltage difference becomes equal to or less than a predetermined value; a current integral amount calculation unit that obtains a current integral amount, the current integral amount being a time integral amount of a current flowing through the secondary battery between the first time point and the second time point; an SOC difference calculation unit that obtains an SOC difference between an SOC at the first time point and an SOC at the second time point; a current correction amount calculation unit that calculates a current error contained in a detection signal output by the current detection unit on the basis of a storage battery capacity, the SOC difference, the current integral amount, and a time from the first time point to the second time point, and sets the current error as a current correction amount; and a current correction unit that performs correction on the detection signal using the current correction amount.

3 . The battery control device according to claim 1 ,
wherein the current correction unit attenuates the calculated current error as time elapses during a period when the current error is not calculated by the current correction amount calculation unit so as to correct the current.

4 . The battery control device according to claim 2 ,
wherein the time-point setting unit calculates each SOC on the basis of the open-circuit voltage, and sets the first and second time points at which an absolute value of the SOC difference is equal to or less than a predetermined value.

5 . The battery control device according to claim 1 ,
wherein the time-point setting unit calculates a difference in a current value flowing through the secondary battery, and sets the first and second time points at which an absolute value of the difference of the current value is equal to or less than a predetermined value.

6 . The battery control device according to claim 1 ,
wherein the time-point setting unit calculates a temporal variation amount of the current flowing through the secondary battery, and sets the first and second time points at which an absolute value of the temporal variation amount of the current flowing through the secondary battery is equal to or less than a predetermined value.

7 . The battery control device according to claim 1 ,
wherein the time-point setting unit calculates an absolute value of the current flowing through the secondary battery, and sets the first and second time points at which an absolute value of the current flowing through the secondary battery is equal to or less than a predetermined value.

8 . The battery control device according to claim 1 ,
wherein the time-point setting unit sets the first and second time points at which a time interval becomes equal to or more than a predetermined value.

9 . The battery control device according to claim 1 ,
wherein the time-point setting unit sets the first time point and the second time point when a temperature of the secondary battery falls within a predetermined range.

10 . The battery control device according to claim 1 ,
wherein the current correction amount calculation unit calculates a plurality of the current correction amounts, wherein the current correction unit performs a weighted average using the plurality of the current correction amounts to obtain an average current correction amount, and corrects the current using the average current correction amount, and wherein a weight in the weighted average is assigned according to an error of each of the plurality of the current correction amounts.

11 . The battery control device according to claim 1 ,
wherein the battery control device is mounted in a vehicle system, wherein the vehicle system is provided with an engine, a motor generator that is driven by power from the secondary battery at the time of powering, and generates regenerative electric power to charge the secondary battery at the time of regenerating, and a system control unit that controls at least the engine and the motor generator; wherein the engine and the motor generator drive a drive system, and wherein the system control unit includes an EV driving mode in which the drive system is driven by the motor generator without using the engine, and an HEV driving mode in which the drive system is driven by the engine and the motor generator.

12 . The battery control device according to claim 11 , further comprising:
a command unit that outputs a command to the system control unit to switch a driving mode to the HEV driving mode in a case where a chance to calculate the current correction amount is equal to or less than a predetermined number of times in the EV driving mode.

13 . The battery control device according to claim 11 , further comprising:
a command unit that outputs a command to the system control unit to increase a ratio of HEV running after the vehicle system starts to run and a predetermined period elapses.

14 . A vehicle system, comprising:
an engine; a motor generator that is driven by power from the secondary battery at the time of powering, and generates regenerative electric power to charge the secondary battery at the time of regenerating; the battery control device according to claim 1 ; and a system control unit that controls at least the engine and the motor generator, wherein the engine and the motor generator drive a drive system, and wherein the system control unit includes an EV driving mode in which the drive system is driven by the motor

Assignees

• Hitachi Automotive Systems Ltd

Inventors

• Ohkawa Keiichiro
• NAKAO Ryohhei

Classifications

• B60L2240/549

  Current · CPC title

• B60W2510/244

  Charge state · CPC title

• Y10S903/93

  Conjoint control of different elements · CPC title

• B60L2260/42

  by adaptive correction · CPC title

• H02J7/00

  Circuit arrangements for charging or discharging batteries or for supplying loads from batteries · CPC title