Power Supply Device, Input-Output Limit Setting Method in Power Supply Device, Vehicle, and Vehicle Control Method

• US 20090321163A1
• Filed: 04/13/2007
• Published: 12/31/2009
• Est. Priority Date: 04/14/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Suzui, Kosuke
• Granted Patent: US 8,127,874 B2
• Time in Patent Office: Days
• US Class Current: 180/65.265
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/442 Series-parallel switching type
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/448 Electrical distribution type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/24 for controlling the temperature of batteries
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2510/081 Speed
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2510/246 Temperature
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 : Brake pedal position
• CPC Class Codes: B60W 2540/16 : Ratio selector position
• CPC Class Codes: B60W 2710/0644 : Engine speed
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: H02J 2310/48 : for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/00 : Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0048 : Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/00714 : in response to battery charging or discharging current
• CPC Class Codes: H02J 7/00719 : in response to degree of gas development in the battery
• CPC Class Codes: H02J 7/007194 : of the battery
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries

Abstract

When a time average of square values of charge-discharge current Ib (square mean value Sqib) exceeds a predetermined reference value Sqref and when state of charge SOC of a battery is higher than a preset reference level SOCref1, the procedure of the invention corrects a basic input limit Wintmp set according to a battery temperature Tb and the state of charge SOC and sets the corrected basic input limit Wintmp to an effective input limit Win* (steps S140, S180, and S190). When the state of charge SOC is lower than a preset reference level SOCref2, the procedure of the invention corrects a basic output limit Wouttmp set according to the battery temperature Tb and the state of charge SOC and sets the corrected basic output limit Wouttmp to an effective output limit Wout* (steps S200 and S210). This arrangement of the invention more adequately sets the effective input limit Win* and the effective output limit Wout*, compared with a conventional technique of simultaneously correcting the effective input limit and the effective output limit based on the temperature Tb of the battery.

Claims

1. A power supply device constructed to input and output electric power, the power supply device comprising:

an accumulator designed to be chargeable and dischargeable;

a temperature sensor constructed to measure temperature of the accumulator;

a charge-discharge current meter constructed to measure a charge-discharge current to be charged into or discharged from the accumulator;

a state-of-charge calculator configured to compute a state of charge as an indication of an amount of electric power dischargeable from the accumulator, based on the measured charge-discharge current;

an input limit setter configured to set a basic input limit, as a maximum allowable electric power to be charged into the accumulator, according to the computed state of charge and the measured temperature, correct the set basic input limit based on the measured charge-discharge current, and set the corrected basic input limit to an effective input limit; and

an output limit setter configured to set an effective output limit, as a maximum allowable electric power to be discharged from the accumulator, according to the computed state of charge and the measured temperature.

2. The power supply device in accordance with claim 1, the power supply device further having:

a square current calculator configured to compute a time average of square values of the measured charge-discharge current,

wherein when the computed time average exceeds a preset average value, the input limit setter makes a decreasing correction of the basic input limit and sets the corrected basic input limit to the effective input limit.

3. The power supply device in accordance with claim 2, wherein when the computed time average exceeds the preset average value, the input limit setter corrects the basic input limit to have a decreasing tendency with elapse of time and sets the corrected basic input limit to the effective input limit.

4. The power supply device in accordance with claim 2, wherein the output limit setter sets a tentative basic output limit, as the maximum allowable electric power to be discharged from the accumulator, according to the measured temperature and, when the computed state of charge is lower than a preset first state-of-charge level, makes a decreasing correction of the tentative basic output limit and sets the decreasingly corrected tentative basic output limit to a basic output limit,

when the computed state of charge becomes lower than a preset second state-of-charge level, which is higher than the first state-of-charge level, in the case of decreasingly correcting the basic input limit, the output limit setter making a decreasing correction of the basic output limit and setting the decreasingly corrected basic output limit to the effective output limit.

5. The power supply device in accordance with claim 1, wherein the output limit setter sets a basic output limit as the maximum allowable electric power to be discharged from the accumulator according to the computed state of charge and the measured temperature, corrects the set basic output limit based on the computed state of charge, and sets the corrected basic output limit to the effective output limit.

6. The power supply device in accordance with claim 1, the power supply device further having:

a voltage sensor configured to measure an inter-terminal voltage of an output terminal of the accumulator; and

an internal pressure sensor configured to measure an internal pressure of the accumulator,

wherein the input limit setter sets the basic input limit as the allowable maximum electric power to be charged into the accumulator according to at least one of the measured inter-terminal voltage and the measured internal pressure, in addition to the computed state of charge and the measured temperature, and

the output limit setter sets a basic output limit as the maximum allowable electric power to be discharged from the accumulator according to at least one of the measured inter-terminal voltage and the measured internal pressure, in addition to the computed state of charge and the measured temperature.

7. A vehicle, comprising:

a driving source configured to output power to a driveshaft linked with an axle of the vehicle;

a motor configured to input and output power from and to the driveshaft;

an accumulator designed to be chargeable and dischargeable and arranged to enable transmission of electric power from and to the motor;

a temperature sensor constructed to measure temperature of the accumulator;

a charge-discharge current meter constructed to measure a charge-discharge current to be charged into or discharged from the accumulator;

a state-of-charge calculator configured to compute a state of charge as an indication of an amount of electric power dischargeable from the accumulator, based on the measured charge-discharge current;

an input limit setter configured to set a basic input limit, as a maximum allowable electric power to be charged into the accumulator, according to the computed state of charge and the measured temperature, correct the set basic input limit based on the measured charge-discharge current, and set the corrected basic input limit to an effective input limit;

an output limit setter configured to set an effective output limit, as a maximum allowable electric power to be discharged from the accumulator, according to the computed state of charge and the measured temperature; and

a controller configured to control the driving source and the motor to charge and discharge the accumulator in a range defined by the set effective input limit and the set effective output limit.

8. The vehicle in accordance with claim 7, the vehicle further having:

a square current calculator configured to compute a time average of square values of the measured charge-discharge current,

wherein when the computed time average exceeds a preset average value, the input limit setter makes a decreasing correction of the basic input limit and sets the corrected basic input limit to the effective input limit.

9. The vehicle in accordance with claim 7, wherein the output limit setter sets a basic output limit as the maximum allowable electric power to be discharged from the accumulator according to the computed state of charge and the measured temperature, corrects the set basic output limit based on the computed state of charge, and sets the corrected basic output limit to the effective output limit.

10. The vehicle in accordance with claim 7, the vehicle further having:

a voltage sensor configured to measure an inter-terminal voltage of an output terminal of the accumulator; and

an internal pressure sensor configured to measure an internal pressure of the accumulator,

wherein the input limit setter sets the basic input limit as the allowable maximum electric power to be charged into the accumulator according to at least one of the measured inter-terminal voltage and the measured internal pressure, in addition to the computed state of charge and the measured temperature, and

the output limit setter sets a basic output limit as the maximum allowable electric power to be discharged from the accumulator according to at least one of the measured inter-terminal voltage and the measured internal pressure, in addition to the computed state of charge and the measured temperature.

11. The vehicle in accordance with claim 7, the vehicle further having:

a state-of-charge display unit configured to display the computed state of charge of the accumulator.

12. An input-output limit setting method in a power supply device equipped with a chargeable and dischargeable accumulator and constructed to input and output electric power, the input-output limit setting method setting an effective input limit as a maximum allowable electric power to be charged into the accumulator and setting an effective output limit as a maximum allowable electric power to be discharged from the accumulator,

the input-output limit setting method comprising:

computing a state of charge as an indication of an amount of electric power dischargeable from the accumulator, based on a charge-discharge current to be charged into or discharged from the accumulator;

setting a basic input limit, as the maximum allowable electric power to be charged into the accumulator, according to the computed state of charge and a temperature of the accumulator, correcting the set basic input limit based on the charge-discharge current, and setting the corrected basic input limit to the effective input limit; and

setting the effective output limit, as the maximum allowable electric power to be discharged from the accumulator, according to the computed state of charge and the temperature of the accumulator.

13. A vehicle control method for controlling a vehicle, the vehicle comprising:

a power supply device equipped with a chargeable and dischargeable accumulator and constructed to input and output electric power;

a driving source configured to output power to a driveshaft linked with an axle of the vehicle; and

a motor configured to enable transmission of electric power to and from the power supply device and to input and output power from and to the driveshaft,

the vehicle control method comprising;

computing a state of charge as an indication of an amount of electric power dischargeable from the accumulator, based on a charge-discharge current to be charged into or discharged from the accumulator;

setting a basic input limit, as a maximum allowable electric power to be charged into the accumulator, according to the computed state of charge and a temperature of the accumulator, correcting the set basic input limit based on the charge-discharge current, and setting the corrected basic input limit to an effective input limit;

setting an effective output limit, as a maximum allowable electric power to be discharged from the accumulator, according to the computed state of charge and the temperature of the accumulator; and

controlling the driving source and the motor to charge and discharge the accumulator in a range defined by the set effective input limit and the set effective output limit.