Electric power system

• US 10,641,227 B2
• Filed: 07/30/2018
• Issued: 05/05/2020
• Est. Priority Date: 08/03/2017
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Namiki, Shigeru, Koizumi, Yuki
• Primary Examiner(s): Vilakazi, Sizo B
• Assistant Examiner(s): Bacon, Anthony L
• Application Number:
  US16/048,371
• Publication Number:
  US 20190040832A1
• Time in Patent Office: 645 Days
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 11/0825 related to prevention of engine restart failure, e.g. disabling automatic stop at low battery state
• CPC Class Codes: F02N 11/0833 Vehicle conditions F02N11/0822, F02N11/0825 take precedence
• CPC Class Codes: F02N 11/0862 characterised by the electrical power supply means, e.g. battery
• CPC Class Codes: F02N 2200/061 Battery state of charge [SOC]
• CPC Class Codes: F02N 2200/062 Battery current
• CPC Class Codes: F02N 2200/063 Battery voltage
• CPC Class Codes: F02N 2200/064 Battery temperature
• CPC Class Codes: F02N 2200/0801 Vehicle speed
• CPC Class Codes: F02N 2200/101 Accelerator pedal position
• CPC Class Codes: F02N 2200/102 Brake pedal position
• CPC Class Codes: F02N 2300/30 characterised by the use of digital means
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G07C 5/0808 Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Provided is an electric power system mounted on a vehicle having an engine, a battery, and a starter that starts the engine. The electric power system includes an SOC estimation part, estimating the SOC of the battery based on a first algorithm; an idling stop control part, permitting implementation of an idling stop control when an estimation result of the SOC estimation part satisfies a predetermined automatic stop condition; a full charge determination part, determining whether the battery is in a full charge state based on a second algorithm different from the first algorithm; and a malfunction determination part, determining that malfunction occurs in the SOC estimation part when the battery is estimated in the full charge state by the full charge determination part and the estimation result of the SOC estimation part does not satisfy the automatic stop condition.

Claims

1. An electric power system that controls an internal-combustion engine based on a state of a battery, comprising:

a first charging state estimation part, estimating a charging state of the battery based on a first algorithm;

an idling stop control part, permitting an implementation of an idling stop control which temporarily stops the internal-combustion engine when an estimation result of the first charging state estimation part satisfies a permissible condition, and prohibits the implementation of the idling stop control when the permissible condition is not satisfied;

a second charging state estimation part, estimating the charging state of the battery based on a second algorithm different from the first algorithm; and

a malfunction determination part, determining that malfunction occurs in an estimation of the charging state of the battery when an estimation result of the second charging state estimation part satisfies a predetermined condition and the estimation result of the first charging state estimation part does not satisfy the permissible condition.

2. The electric power system according to claim 1, wherein when the estimation result of the second charging state estimation part satisfies the predetermined condition, the malfunction determination part determines whether the estimation result of the first charging state estimation part satisfy the permissible condition.

3. The electric power system according to claim 1, wherein the predetermined condition is satisfied when the battery is estimated in a full charge state by the second charging state estimation part.

4. The electric power system according to claim 1, wherein when the estimation result of the second charging state estimation part satisfies the predetermined condition and the estimation result of the first charging state estimation part does not satisfy the permissible condition, the malfunction determination part determines that malfunction occurs in the first charging state estimation part.

5. The electric power system according to claim 1, wherein the permissible condition is satisfied when the charging rate of the battery is estimated to be equal or larger than a predetermined threshold by the first charging state estimation part, and

the idling stop control part decreases the predetermined threshold when the malfunction determination part determines that malfunction occurs.

6. The electric power system according to claim 1, wherein when the malfunction determination part determines that malfunction occurs, the first charging state estimation part corrects at least one of the first algorithm and parameters used in the first algorithm.

7. The electric power system according to claim 6, wherein the first algorithm is an estimation method that estimates the charging state of the battery by using a map associating an open voltage of the battery with the charging state of the battery, and

the first charging state estimation part revises the map when the malfunction determination part determines that malfunction occurs.

8. The electric power system according to claim 6, wherein the first algorithm is an estimation method that estimates the charging state of the battery by calculating an accumulated value of a charging current of the battery and a discharging current opposite to the charging current, and

the first charging state estimation part adds a predetermined value to the accumulated value when the malfunction determination part determines that malfunction occurs.

9. The electric power system according to claim 1, further comprising a charge control part that charges the battery until the first charging state estimation part determines that the battery is in the full charge state, when the malfunction determination part determines that malfunction occurs.

10. The electric power system according to claim 1, wherein when a change rate of the charging current of the battery is lower than a threshold set to a value slightly greater than 0, the second charging state estimation part estimates that the battery is in the full charge state.

11. The electric power system according to claim 2, wherein the predetermined condition is satisfied when the battery is estimated in a full charge state by the second charging state estimation part.

12. The electric power system according to claim 2, wherein when the estimation result of the second charging state estimation part satisfies the predetermined condition and the estimation result of the first charging state estimation part does not satisfy the permissible condition, the malfunction determination part determines that malfunction occurs in the first charging state estimation part.

13. The electric power system according to claim 2, wherein the permissible condition is satisfied when the charging rate of the battery is estimated to be equal or larger than a predetermined threshold by the first charging state estimation part, and

the idling stop control part decreases the predetermined threshold when the malfunction determination part determines that malfunction occurs.

14. The electric power system according to claim 2, wherein when the malfunction determination part determines that malfunction occurs, the first charging state estimation part corrects at least one of the first algorithm and parameters used in the first algorithm.

15. The electric power system according to claim 14, wherein the first algorithm is an estimation method that estimates the charging state of the battery by using a map associating an open voltage of the battery with the charging state of the battery, and

the first charging state estimation part revises the map when the malfunction determination part determines that malfunction occurs.

16. The electric power system according to claim 14, wherein the first algorithm is an estimation method that estimates the charging state of the battery by calculating an accumulated value of a charging current of the battery and a discharging current opposite to the charging current, and

the first charging state estimation part adds a predetermined value to the accumulated value when the malfunction determination part determines that malfunction occurs.

17. The electric power system according to claim 2, further comprising a charge control part that charges the battery until the first charging state estimation part determines that the battery is in the full charge state, when the malfunction determination part determines that malfunction occurs.

18. The electric power system according to claim 2, wherein when a change rate of the charging current of the battery is lower than a threshold set to a value slightly greater than 0, the second charging state estimation part estimates that the battery is in the full charge state.