Status detector for power supply, power supply, and initial characteristic extracting device for use with power supply

• US 8,054,045 B2
• Filed: 10/13/2009
• Issued: 11/08/2011
• Est. Priority Date: 03/07/2005
• Status: Active Grant

• Current Assignee: Vehicle Energy Japan, Inc.
• Original Assignee: Hitachi Vehicle Energy, Ltd. (Hitachi, Ltd.)
• Inventors: Takahashi, Hirotaka, Emori, Akihiko, Kudo, Akihiko, Kawahara, Youhei, Shida, Masami, Yamauchi, Shuko
• Primary Examiner(s): WILLIAMS, ARUN C
• Application Number:
  US12/577,907
• Publication Number:
  US 20100030499A1
• Time in Patent Office: 756 Days
• Field of Search: 320/127, 320/137, 320/165, 320/132, 324/434, 324/430, 324/431, 324/432, 324/552
• US Class Current: 320/127
• 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 2250/16 by display
• CPC Class Codes: B60L 3/0038 relating to sensors
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: H02J 7/0049 Detection of fully charged condition
• CPC Class Codes: H02J 7/005 Detection of state of health [SOH]
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

In a status detector for a power supply, a power supply, and an initial characteristic extracting device for use with the power supply, a measuring unit obtains measured values of at least current, voltage and temperature of the electricity accumulating unit. A processing unit executes status detection of the electricity accumulating unit by using the measured values and the characteristic information of the electricity accumulating unit which is stored in a memory unit. A discrepancy detecting unit detects the presence of a discrepancy away from a theoretical value when a result of the status detection is changed over a predetermined threshold or reversed with respect to the measured values. A modifying unit modifies the characteristic information depending on the detected discrepancy.

Claims

1. A status detector used for a power supply which provides electricity accumulating means and measuring means for measuring at least current, voltage, and temperature of the electricity accumulating means, comprising:

memory means for storing characteristic information of said electricity accumulating means; and

processing means for executing calculation for detecting state of charge of said electricity accumulating means by using information including the measured information obtained from the output of the measuring means and the characteristic information which is stored in said memory means;

wherein said processing means comprises;

a first state of charge detecting means for obtaining a first state of charge of said electricity accumulating means by using information including an open circuit voltage of said electricity accumulating means, and said open circuit voltage is obtained by using information including the measured information and the characteristic information;

a second state of charge detecting means for obtaining a second state of charge of said electricity accumulating means by using information including the current information of said electricity accumulating means obtained from the output of said measuring means;

an error detecting means for obtaining a product of a current of said electricity accumulating means obtained from the output of said measuring means, and an internal DC resistance of said electricity accumulating means;

weight deciding means for obtaining first and second weights which weight to said first state of charge and said second state of charge by using the product of the current and the internal DC resistance obtained by said error detecting means; and

means for obtaining the state of charge of said electricity accumulating means by combining a state of charge which is obtained by weighting the first weight to said first state of charge and a state of charge which is obtained by weighting the second weight to said second state of charge.

2. The status detector used for the power supply according to claim 1,

wherein the first weight is decreased and the second weight is increased when the current of said electricity accumulating means obtained from the output of said measuring means is increased or the internal DC resistance of said electricity accumulating means is increased, and

the first weight is increased and the second weight is decreased when the current of said electricity accumulating means obtained from the output of said measuring means is increased or the internal DC resistance of said electricity accumulating means is decreased.

3. The status detector used for the power supply according to claim 1, further comprising:

discrepancy detecting means for detecting the presence of a discrepancy away from a theoretical value when the state of charge of said electricity accumulating means obtained by said processing means is changed over a predetermined threshold or reversed with respect to the measured information obtained from the output of said measuring means; and

modifying means for modifying the characteristic information stored in said memory means depending on the discrepancy detected by said discrepancy detecting means.

4. The status detector used for the power supply according to claim 3,

wherein the first weight is decreased and the second weight is increased when the current of said electricity accumulating means obtained from the output of said measuring means is increased or the internal DC resistance of said electricity accumulating means is increased, and

the first weight is increased and the second weight is decreased when the current of said electricity accumulating means obtained from the output of said measuring means is decreased the internal DC resistance of said electricity accumulating means is decreased.

5. A power supply comprising:

electricity accumulating means;

measuring means for measuring at least current, voltage, and temperature of said electricity accumulating means; and

a status detector for detecting a state of charge of said electricity accumulating means;

wherein said status detector comprises;

memory means for storing characteristic information of said electricity accumulating means; and

processing means for executing calculation for detecting state of charge of said electricity accumulating means by using information including the measured information obtained from the output of the measuring means and the characteristic information which is stored in said memory means;

wherein said processing means comprises;

a first state of charge detecting means for obtaining a first state of charge of said electricity accumulating means by using information including an open circuit voltage of said electricity accumulating means, and said open circuit voltage is obtained by using information including the measured information and the characteristic information;

a second state of charge detecting means for obtaining a second state of charge of said electricity accumulating means by using information including the current information of said electricity accumulating means obtained from the output of said measuring means;

an error detecting means for obtaining a product of a current of said electricity accumulating means obtained from the output of said measuring means, and for an internal DC resistance of said electricity accumulating means;

weight deciding means for obtaining first and second weights which weight to said first state of charge and said second state of charge by using the product of the current and the internal DC resistance obtained by said error detecting means; and

means for obtaining the state of charge of said electricity accumulating means by combining a state of charge which is obtained by weighting the first weight to said first state of charge and a state of charge which is obtained by weighting the second weight to said second state of charge.

6. The power supply according to claim 5,

wherein the first weight is decreased and the second weight is increased when the current of said electricity accumulating means obtained from the output of said measuring means is increased or the internal DC resistance of said electricity accumulating means is increased, and

the first weight is increased and the second weight is decreased when the current of said electricity accumulating means obtained from the output of said measuring means is decreased or the internal DC resistance of said electricity accumulating means is decreased.

7. The power supply according to claim 5, further comprising:

discrepancy detecting means for detecting the presence of a discrepancy away from a theoretical value when the state of charge of said electricity accumulating means obtained by said processing means is changed over a predetermined threshold or reversed with respect to the measured information obtained from the output of said measuring means; and

modifying means for modifying the characteristic information stored in said memory means depending on the discrepancy detected by said discrepancy detecting means.

8. The power supply according to claim 7,

wherein the first weight is decreased and the second weight is increased when the current of said electricity accumulating means obtained from the output of said measuring means is increased or the internal DC resistance of said electricity accumulating means is increased, and

the first weight is increased and the second weight is decreased when the current of said electricity accumulating means obtained from the output of said measuring means is decreased or the internal DC resistance of said electricity accumulating means is decreased.