Apparatus for estimating remaining power amount of battery employing a polarization voltage

• US 10,353,010 B2
• Filed: 02/16/2015
• Issued: 07/16/2019
• Est. Priority Date: 02/21/2014
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Hotta, Shin
• Primary Examiner(s): Grant, Robert J
• Assistant Examiner(s): Trischler, John T
• Application Number:
  US14/622,988
• Publication Number:
  US 20150241516A1
• Time in Patent Office: 1,611 Days
• Field of Search: 320149
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• 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 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

There is provided a battery remaining-life estimation apparatus that includes a memory, and a circuit. The memory is configured to store information about a polarization-voltage curve of a secondary battery, the information being stored with a correlation with a current value and a temperature of the secondary battery. The circuit is configured to estimate a remaining power of the secondary battery, the remaining power being estimated based on a discharge curve of the secondary battery. The circuit obtains the polarization-voltage curve based on the information in the memory, the polarization-voltage curve being correlated with the current value and the temperature of the secondary battery. The circuit also estimates the discharge curve by subtracting the obtained polarization-voltage curve from an open-circuit voltage curve obtained for the secondary battery.

Claims

1. A battery remaining-life estimation apparatus, comprising:

a memory configured to store a plurality of parameters defining a shape of a polarization-voltage curve, wherein the plurality of parameters includes a first parameter associated only with a temperature value of a battery and a second parameter associated both with the temperature value and a current value of the battery; and

a processor configured to obtain an open-circuit voltage curve of the battery and to obtain the polarization-voltage curve based on the plurality of parameters stored in the memory, wherein the processor is configured to control the battery to supply a power to a connected power consumption device,

wherein the processor is configured to estimate a remaining power amount of the secondary battery based on a discharge curve, and wherein the discharge curve is obtained by subtracting the polarization-voltage curve from the open-circuit voltage curve of the secondary battery, and

wherein the polarization-voltage curve includes a first curve portion and a second curve portion, and wherein the first curve portion satisfies an equation 1;

V=aI+b 

 

(equation

     1)

wherein a is a coefficient proportional to a discharge current, b is a constant component corresponding to the remaining of the diffusion polarization, I is a value of a discharge current of the battery, and V is a polarization voltage;

wherein for the second curve portion, the memory stores a parameter defining a shape of a curve as typical parameters, the curve being obtained by differentiating the second curve portion with respect to the amount of charge; and

wherein when determining the discharge curve, the second curve portion is reproduced by integrating the differential curve stored in the memory.

2. The battery remaining-life estimation apparatus according to claim 1, wherein

for the first curve portion of the polarization-voltage curve where a voltage change responding to a change in amount of charge is small, the memory stores a proportional coefficient and a constant component as typical parameters, the proportional coefficient being of a component proportional to a discharge current, and

for the second curve of the polarization voltage curve is where the voltage change is large.

3. The battery remaining-life estimation apparatus according to claim 1, wherein

the memory stores the information about the polarization-voltage curve also with a correlation with a capacity retention of the secondary battery.

4. The battery remaining-life estimation apparatus according to claim 1, wherein

the processor estimates the remaining power based on an estimated temperature change of the secondary battery.

5. The battery remaining-life estimation apparatus according to claim 1, wherein

the processor obtains the polarization-voltage curve based on current and temperature information of the secondary battery, the information being obtained by communication.