Charge/discharge control device for secondary battery and hybrid vehicle using the same

• US 8,336,651 B2
• Filed: 07/27/2007
• Issued: 12/25/2012
• Est. Priority Date: 08/01/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Nishi, Yuji, Yamauchi, Tomokazu
• Primary Examiner(s): Ebner, Katy M
• Assistant Examiner(s): Frick, Emma K
• Application Number:
  US12/375,587
• Publication Number:
  US 20100000809A1
• Time in Patent Office: 1,978 Days
• Field of Search: 180/65.29, 180/65.21, 320/132, 320/134, 320/136, 702/63, 324/426, 701/36
• US Class Current: 180/65.29
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 2250/26 by pedal actuation
• CPC Class Codes: B60L 2260/44 by parameter estimation
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: B60L 58/14 Preventing excessive discharging
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/16 responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: B60L 58/26 by cooling
• 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: H01M 10/44 : Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/48 : Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H02J 7/00302 : Overcharge protection
• CPC Class Codes: H02J 7/00306 : Overdischarge protection
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• 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
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

A state estimation value indicating a battery state is successively calculated from time to time according to a battery model capable of dynamically estimating the internal state of the secondary battery by using an inspection value of a sensor group indicating the secondary battery behavior. By using the sate estimation value at each moment estimated by the battery model expression at each predetermined cycle, an I/O-enabled time is predicted when a predetermined power is continuously inputted (charged) or outputted (discharged) from the current moment. A load operation instruction of the secondary battery is set so as to avoid overcharge and over-discharge of the secondary battery according to the operation request to the load and by considering the predicted characteristics between input/output power and input/output-allowed time.

Claims

1. A charge/discharge control device for a secondary battery configured to be capable of receiving/transmitting electric power from/to a load, the device being programmed to have:

a battery state estimation portion sequentially calculating a state estimation value indicative of a battery state in the interior of said secondary battery according to a battery model capable of dynamically estimating an internal state of said secondary battery, based on a detection value by a sensor provided for said secondary battery;

a deterioration rate prediction portion for predicting a deterioration rate of the secondary battery in a case where said secondary battery continuously inputs/outputs a prescribed power from a present time, based on said state estimation value at the present time estimated by said battery state estimation portion; and

a load control portion generating an operation command for said load in consideration of the deterioration rate predicted by said deterioration rate prediction portion, based on an operation request to said load,

wherein said deterioration rate prediction portion predicts respective said deterioration rates for a plurality of said prescribed power at the present time.

2. The charge/discharge control device for a secondary battery according to claim 1, further comprising a deterioration degree estimation portion estimating a deterioration degree or a remaining lifetime of said secondary battery, based on the detection value by said sensor, wherein

said load control portion finds a deterioration rate range permissible at a present time, in consideration of said deterioration degree or said remaining lifetime estimated by said deterioration degree estimation portion, and in addition, generates an operation command for said load with restriction within such a charge/discharge power range of said secondary battery in that the deterioration rate predicted by said deterioration rate prediction portion falls within said deterioration rate range.

3. The charge/discharge control device for a secondary battery according to claim 1, wherein

said secondary battery is formed of a lithium-ion battery, and

said state estimation values include a lithium ion concentration distribution in the interior of the secondary battery.

4. The charge/discharge control device for a secondary battery according to claim 1, wherein

said battery model includes a model equation estimating a concentration distribution of a material which ionizes by an electrode reaction, and

said battery estimation portion sequentially calculates said state estimation value which reflects said concentration distribution estimated according to said model equation.

5. A hybrid vehicle comprising:

an internal combustion engine and a motor configured to be capable of generating a driving power of a vehicle;

a control device determining a driving power output by each of said internal combustion engine and said motor such that a required driving power for said vehicle as a whole is secured;

a secondary battery configured to be capable of receiving/transmitting electric power from/to said motor; and

a charge/discharge control device for said secondary battery, wherein

said charge/discharge control device is programmed to sequentially calculate a state estimation value indicative of a battery state in the interior of said secondary battery according to a battery model capable of dynamically estimating an internal state of said secondary battery, based on a detection value by a sensor provided for said secondary battery, and in addition, predict a deterioration rate of the secondary battery in a case where said secondary battery continuously inputs/outputs a prescribed power from a present time, based on said state estimation value at the present time as estimated, and

said control device is programmed to set an input/output permissible power of said motor with restriction within such a charge/discharge power range of said secondary battery in that deterioration of said secondary battery does not proceed significantly, based on said deterioration rate predicted by said charge/discharge control device, and in addition, determine a torque command value of said motor with restriction such that input/output power of said motor falls within a range of said input/output permissible power,

wherein said charge/discharge control device is programmed to predict respective said deterioration rates for a plurality of said prescribed power at the present time, and

said control device is programmed to set the input/output permissible power of said motor based on said deterioration rates predicted for said plurality of prescribed power.

6. The hybrid vehicle according to claim 5, wherein

said charge/discharge control device is further programmed to estimate a deterioration degree or a remaining lifetime of said secondary battery, based on the detection value by said sensor, and

said control device is programmed to find a deterioration rate range permissible at a present time, in consideration of said deterioration degree or said remaining lifetime estimated by said charge/discharge control device, and in addition, determine a charge/discharge power range of said secondary battery with restriction such that the predicted deterioration rate falls within said deterioration rate range.

7. The hybrid vehicle according to claim 5, wherein

said secondary battery is formed of a lithium-ion battery, and

said state estimation value includes a lithium ion concentration distribution in the interior of the secondary battery.

8. The hybrid vehicle according to claim 5, wherein

said battery model includes a model equation estimating a concentration distribution of a material which ionizes by an electrode reaction, and

said control device is programmed to sequentially calculate said state estimation value which reflects said concentration distribution estimated according to said model equation.

9. The hybrid vehicle according to claim 5, wherein said sensor is selected from the group consisting of a current sensor and a voltage sensor.