Method and apparatus for calculating battery state and apparatus for controlling power voltage in vehicle

• US 7,777,446 B2
• Filed: 01/31/2007
• Issued: 08/17/2010
• Est. Priority Date: 01/31/2006
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation, Nippon Soken, Inc. (DENSO Corporation)
• Original Assignee: DENSO Corporation, Nippon Soken, Inc. (DENSO Corporation)
• Inventors: Ueda, Kenji, Hashikawa, Atsushi, Kato, Akira, Mizuno, Satoru, Tanaka, Katsunori, Sakai, Shoji
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): Berhanu; Samuel
• Application Number:
  US11/700,183
• Publication Number:
  US 20070182385A1
• Time in Patent Office: 1,294 Days
• Field of Search: 320/104, 320/132, 320/134, 324/426, 324/427
• US Class Current: 320/104
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/1438 in combination with power supplies for loads other than batteries
• CPC Class Codes: H02J 7/16 Regulation of the charging current or voltage by variation of field
• CPC Class Codes: H02J 7/24 using discharge tubes or semiconductor devices
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

An apparatus is provided to control a power voltage on a power-supplying line extending from a generator and connecting to a battery and eclectic loads. The apparatus is mounted on a vehicle and comprises a detecting device, a calculator, and a controller. The detecting device detects pairs of voltage and current of the battery. The calculator calculating a control current on the basis of the detected pairs of voltage and current and a target voltage for the power voltage. The pairs of voltage and current are used to calculate an internal resistance and/or a regression line of the battery. The controller controlling a charge and discharge current of the battery on the basis of the control current so that the power voltage is controlled to the target voltage.

Claims

1. An apparatus for controlling a voltage of power on a power-supplying line extending from an on-vehicle generator and connecting to an on-vehicle battery and on-vehicle eclectic loads, the apparatus being mounted on a vehicle, the apparatus comprising:

a detecting device detecting pairs of voltage and current of the battery repeatedly at intervals;

a calculator calculating a control current based on the detected pairs of voltage and current and a target voltage given to the voltage of the power; and

a controller controlling a charge and discharge current of the battery based on the control current such that the voltage of the power is controlled at the target voltage,

wherein the calculator is provided with

internal resistance obtaining means for obtaining an internal resistance of the battery based on the pairs of voltage and current;

first calculating means for calculating a value of the control current based on the target voltage and the internal resistance;

first providing means for providing the control current as a command to the controller;

first determining means for determining whether or not an error between an actual voltage of the battery and the target voltage is within an allowable range;

regression line obtaining means for obtaining a regression line defining a relationship between the voltage and the current of the battery by using the pairs of voltage and current if it is determined by the first determining means that the error is within the allowable range;

second calculating means for re-calculating a value of the control current based on the target voltage and the regression line; and

second providing means for re-providing the control current as the command to the controller.

2. The apparatus of claim 1, wherein the calculator is provided with

second determining means for re-determining whether or not the error between the actual voltage of the battery and the target voltage is within the allowable range;

shifting means for shifting the regression line to a further regression line based on a latest pair of voltage and current among the measured pairs of voltage and current if it is determined by the second determining means that the error is within the allowable range;

third calculating means for re-calculating the value of the control current based on the target voltage and the shifted regression line; and

third providing means for re-providing the control current as command to the controller.

3. The apparatus of claim 2, wherein the calculator is provided with

third determining means for re-determining whether or not the error between the actual voltage of the battery and the target voltage is within the allowable range;

amending means for amending a slope of the shifted regression line if it is determined by the third determining means that the error is within the allowable range;

fourth calculating means for re-calculating the value of the control current based on the target voltage and the shifted and slope-amended regression line; and

fourth providing means for re-providing the control current as the command to the controller.

4. The apparatus of claim 1, wherein the controller is arranged separately from the generator and arranged to be present in a path connecting the power-supplying line and the battery.

5. The apparatus of claim 1, wherein the controller is arranged in the generator.

6. An apparatus for controlling a voltage of power on a power-supplying line extending from an on-vehicle generator and connecting to an on-vehicle battery and on-vehicle eclectic loads, the apparatus being mounted on a vehicle, the apparatus comprising:

a detecting device detecting pairs of voltage and current of the battery repeatedly at intervals;

a calculator calculating a control current based on the detected pairs of voltage and current and a target voltage given to the voltage of the power; and

a controller controlling a charge and discharge current of the battery based on the control current such that the voltage of the power is controlled at the target voltage,

the calculator is provided with

first obtaining means for obtaining a regression line defining a relationship between the voltage and the current of the battery based on the pairs of voltage and current and the target voltage;

first calculating means for calculating a value of the control current based on the target voltage and the regression line;

first providing means for providing the control current as a command to the controller;

determining means for determining whether or not an error between an actual voltage of the battery and the target voltage is within an allowable range;

second obtaining means for re-obtaining a further regression line for the battery based on the pairs of voltage and current and the target voltage if it is determined by the determining means that the error is within the allowable range;

second calculating means for calculating a further value of the control current based on the target voltage and the further regression line; and

second providing means for re-providing the further control current as a command to the controller.

7. An apparatus for controlling a voltage of power on a power-supplying line extending from an on-vehicle generator and connecting to an on-vehicle battery and on-vehicle eclectic loads, the apparatus being mounted on a vehicle, the apparatus comprising:

a detecting device detecting pairs of voltage and current of the battery repeatedly at intervals;

a calculator calculating a control current on the basis of the detected pairs of voltage and current and a target voltage given to the voltage of the power; and

a controller controlling a charge and discharge current of the battery on the basis of the control current such that the voltage of the power is controlled at the target voltage,

wherein the calculator includes obtaining means for obtaining a plurality of regression lines each defining a relationship between the voltage and the current of the battery based on the pairs of voltage and current and the target voltage;

calculating means for calculating a value of the control current based on a target voltage and at least one of the regression lines;

providing means for providing the control current as a command to the controller;

determining means for determining whether or not an error between an actual voltage of the battery and the target voltage is within an allowable range; and

using means for selectively using one of the regression lines in calculating the value of the control current, depending on results determined by the determining means.

8. An apparatus for controlling a voltage of power on a power-supplying line extending from an on-vehicle generator and connecting to an on-vehicle battery and on-vehicle eclectic loads, the apparatus being mounted on a vehicle, the apparatus comprising:

a detecting device detecting pairs of voltage and current of the battery repeatedly at intervals;

a calculator calculating a control current based on the detected pairs of voltage and current and a target voltage given to the voltage of the power; and

a controller controlling a charge and discharge current of the battery on the basis of the control current such that the voltage of the power is controlled at the target voltage,

wherein the calculator is configured to obtain a regression line defining a relationship between the voltage and the current of the battery based on the pairs of voltage and current and the target voltage;

calculate a value of the control current on the basis of the target voltage and the regression line;

provide the control current as a command to the controller;

determine whether or not an error between an actual voltage of the battery and the target voltage is within an allowable range; and

amend the regression line if it is determined the error is not within the allowable range.

9. The apparatus of claim 8, wherein the calculator is configured to amend a slope angle of the regression line in a graph so as to make the error smaller, the pairs of voltage and current being plotted in the graph.

10. An apparatus for calculating an electric quantity indicating a charged state of a battery being mounted on a vehicle, the battery being connected via a line to an on-vehicle generator and on-vehicle electric loads, the apparatus comprising:

a detecting device detecting pairs of voltage and current of the battery repeatedly at intervals; and

a calculator configured to calculate a first regression line defining a relationship between the voltage and the current of the battery based on the pairs of voltage and current, determine whether or not the first regression line has accuracy sufficient for calculating the electric quantity;

shift the first regression line to a second regression line for the battery based on a latest of voltage and current among the measured pairs of voltage and current if it is determined that the first regression line does not have the accuracy sufficient for calculating the electric quantity; and

calculate, as the electric quantity, the current of the battery by applying the voltage of the battery to the second regression line.

11. The apparatus of claim 10, wherein the calculator is configured to shift the first regression line such that a shifted distance from the first regression line to the second regression line is the shortest in a graph in which the pair of voltage and current are plotted.

12. An apparatus for calculating an electric quantity indicating a charged state of a battery being mounted on a vehicle, the battery being connected via a line to an on-vehicle generator and on-vehicle electric loads, the apparatus comprising:

a detecting device detecting pairs of voltage and current of the battery repeatedly at intervals; and

a calculator configured to calculate a first regression line defining a relationship between the voltage and the current of the battery based on the pairs of voltage and current, determine whether or not the first regression line has accuracy sufficient for calculating the electric quantity;

shift the first regression line to a second regression line based on a latest pair of voltage and current among the measured pairs of voltage and current if it is determined that the first regression line does not have the accuracy sufficient for calculating the electric quantity; and

calculate, as the electric quantity, the voltage of the battery by applying the current of the battery to the second regression line.

13. A method of calculating an electric quantity indicating a charged state of a battery being mounted on a vehicle, the battery being connected via a line of an on-vehicle generator and on-vehicle electric loads, the method comprising steps of:

determining whether the battery is either in a discharge state or in a charge state;

selecting one regression line depending on a determined result by the determining step, from a plurality of types of regression lines prepared beforehand depending on whether the battery is in the discharge state or the charge state, each regression line defining a relationship between voltage and current of the battery; and

calculating the electric quantity by using the selected one regression line.

14. The method of claim 13, wherein the plurality of types of regression lines are four regression lines consisting of a first regression line used when the battery is in the discharge state and the current of the battery is on the increase, a second regression line used when the battery is in the discharge state and the current of the battery is on the decrease, a third regression line used when the battery is in the charge state and the current of the battery is on the increase, and a fourth regression line used when the battery is in the charge state and the current of the battery is on the decrease.