IMBALANCE REDUCTION CIRCUIT, POWER SUPPLY DEVICE, AND IMBALANCE REDUCTION METHOD

• US 20110121785A1
• Filed: 07/06/2009
• Published: 05/26/2011
• Est. Priority Date: 07/31/2008
• Status: Abandoned Application

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Iida, Takuma, Kimura, Tadao
• Application Number:
  US13/056,035
• Publication Number:
  US 20110121785A1
• Time in Patent Office: Days
• US Class Current: 320/118
• CPC Class Codes: H01M 10/443 in response to temperature
• 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: H01M 10/486 for measuring temperature
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• 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 imbalance reduction circuit is configured to include: a temperature-related information acquisition unit for acquiring temperature-related information related to the temperature of a plurality of electric accumulators; a discharge unit for executing an equalization process for discharging the plurality of electric accumulators until terminal voltages of the respective electric accumulators become substantially equal to one another; and an equalization controller for prohibiting the discharge unit from executing the equalization process, when the temperature-related information acquired by the temperature-related information acquisition unit satisfies a low temperature condition that is set as a condition where the discharge performance of the plurality of electric accumulators deteriorates.

Claims

1. An imbalance reduction circuit, comprising:

a temperature-related information acquisition unit for acquiring temperature-related information related to the temperature of a plurality of electric accumulators;

a discharge unit for executing an equalization process for discharging the plurality of electric accumulators until terminal voltages of the respective electric accumulators become substantially equal to one another; and

an equalization controller for prohibiting the discharge unit from executing the equalization process, when the temperature-related information acquired by the temperature-related information acquisition unit satisfies a low temperature condition that is set as a condition where the discharge performance of the plurality of electric accumulators deteriorates.

2. The imbalance reduction circuit according to claim 1, wherein the temperature-related information acquisition unit acquires, as the temperature-related information, a temperature that the temperature of the plurality of electric accumulators is predicted to reach in the future.

3. The imbalance reduction circuit according to claim 2, wherein the temperature-related information acquisition unit acquires information on an ambient temperature as the temperature-related information.

4. The imbalance reduction circuit according to claim 3, wherein the temperature-related information acquisition unit receives a predictive value of an ambient temperature that is transmitted from an external transmission device, as the information on an ambient temperature.

5. The imbalance reduction circuit according to claim 4, wherein

the plurality of electric accumulators are installed in a vehicle, and

the temperature-related information acquisition unit receives, as the information on an ambient temperature, an ambient temperature that is measured in another vehicle existing on a route in a traveling direction of a base vehicle.

6. The imbalance reduction circuit according to claim 1, wherein

the temperature-related information acquisition unit acquires the temperature of the electric accumulators and an ambient temperature as the temperature-related information, and

the equalization controller prohibits the discharge unit from executing the equalization process, when at least either the temperature of the electric accumulators or the ambient temperature that are acquired by the temperature-related information acquisition unit satisfies the low temperature condition.

7. The imbalance reduction circuit according to claim 1, wherein the low temperature condition is a condition where the temperature-related information indicates a temperature lower than a predetermined reference temperature, and the imbalance reduction circuit further comprises:

a SOC detector for detecting the SOC of the plurality of electric accumulators; and

a reference temperature setting unit for setting the reference temperature such that the reference temperature becomes lower as the SOC detected by the SOC detector increases.

8. The imbalance reduction circuit according to claim 1, further comprising:

a voltage detector for detecting a terminal voltage of each of the plurality of electric accumulators,

wherein the discharge unit executes the equalization process when a voltage indicating a fluctuation of each terminal voltage detected by the voltage detector exceeds a pre-set threshold voltage and the temperature-related information acquired by the temperature-related information acquisition unit does not satisfy the low temperature condition.

9. A power supply device, comprising:

the imbalance reduction circuit described in claim 1; and

the plurality of electric accumulators.

10. An imbalance reduction method, comprising:

a step in which a temperature-related information acquisition unit acquires temperature-related information related to the temperature of a plurality of electric accumulators;

a step in which a discharge unit executes an equalization process for discharging the plurality of electric accumulators until terminal voltages of the respective electric accumulators become substantially equal to one another; and

a step in which an equalization controller prohibits the discharge unit from executing the equalization process, when the temperature-related information acquired by the temperature-related information acquisition unit satisfies a predetermined low temperature condition.