POWER STORAGE SERVICE SYSTEM

• US 20170170668A1
• Filed: 12/13/2016
• Published: 06/15/2017
• Est. Priority Date: 12/15/2015
• Status: Active Grant

• Current Assignee: Yokogawa Electric Corporation
• Original Assignee: Yokogawa Electric Corporation
• Inventors: HAYASHIZAKI, Hironori, MURAI, Jun, HORIE, Hideaki, YOSHITAKE, Satoshi, TANAKA, Ryuuta
• Granted Patent: US 10,361,569 B2
• Time in Patent Office: Days
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/3647 for determining the ability of a battery to perform a critical function, e.g. cranking
• CPC Class Codes: G01R 31/3832 without measurement of battery voltage
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H01M 10/4207 for several batteries or cells simultaneously or sequentially
• 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: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0032 disconnection of loads if battery is not under charge, e.g. in vehicle if engine is not running
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/005 Detection of state of health [SOH]
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The present invention is a power storage service system including: quantitatively grasping the time leading up to the expression of the abnormality; capable determining possible or impossible of avoiding stopping of the function of the assembled battery system. According to the invention, a maintenance operator and a maintenance service supplier of the assembled battery system have a time margin to plan a response schedule and to prepare responding, and it can reduce the cost of responding to the maintenance by reducing and optimizing the number of response.

One aspect of the present invention is a power storage service system configured to control a power system using an assembled battery system including a plurality of unit cells, the power storage service system including: a first measurer configured to measure a self-discharge current difference among the plurality of the unit cells; and a second measurer configured to obtain a residual time of the assembled battery using the self-discharge current difference measured by the first measurer.

Claims

1. A power storage service system configured to control a power system using an assembled battery system including a plurality of unit cells, the power storage service system comprising:

a first measurer configured to measure a self-discharge current difference among the plurality of the unit cells; and

a second measurer configured to obtain a residual time of the assembled battery using the self-discharge current difference measured by the first measurer.

2. The power storage service system according to claim 1, wherein the first measurer comprises:

a third measurer configured to measure a residual capacity of the each of the unit cells and to output a residual capacity measurement value;

a residual capacity equalizer configured to determine a targeted residual capacity based on the residual capacity of the each of the unit cells obtained by the third measurer, to adjust the residual capacity of the each of the unit cells to the targeted residual capacity, and to output the adjusted residual capacity as a residual capacity equalization value;

a time stamper configured to record at least an operation starting time, an operation ending time, and a measuring time of the residual capacity, of the residual capacity equalizer as a time stamp result;

a time stamp result storage configured to store the time stamp result recorded by the time stamper;

a current value detector configured to detect a current value of the assembled battery system and output the current value as a residual capacity equalization current value;

a current value storage configured to store the residual capacity equalization current value obtained from the current value detector;

a first obtainer configured to obtain a equalization adjustment quantity for equalizing the residual capacity of the each of the unit cells using the residual capacity equalization current value obtained from the third measurer, the time stamp result stored in the time stamp result storage, and the residual capacity equalization current value stored in the current value storage; and

a second obtainer configure to obtain the self-discharge current difference from the residual capacity measurement value obtained from the third measurer, the time stamp result stored in the time stamp result storage, and the equalization adjustment quantity obtained from the first obtainer.

3. The power storage service system according to claim 2, further comprising:

a fourth measurer configured to measure a voltage of each of the unit cells;

wherein the third measurer detects the residual capacity of the unit cell by using a first differential characteristic curve of the voltage value of the unit cell measured by the fourth measurer and the current value of the assembled battery measured by the current detector, a second differential characteristic curve as a criterion, and an optimization function.

4. The power storage service system according to claim 2, wherein the first obtainer integrates the residual capacity equalization current value based on the operation starting time and the operation ending time stored in the time stamper.

5. The power storage service system according to claim 2, wherein the second obtainer obtains the self-discharge current difference based on a value obtained from the residual capacity of the unit cell measured by the third measurer by using a calculation method including at least a maximum value, a minimum value, an average value, and a multiplication of a coefficient.

6. The power storage service system according to claim 2, wherein the second obtainer obtains the self-discharge current value based on the residual capacity measured value of at least the one unit cell obtained from the third measurer.

7. The power storage service system according to claim 2, further comprising:

a residual capacity limit value setter configured to set an upper limit value and a lower limit value of the residual capacity measurement value obtained from the third measurer; and

a residual capacity limiter configured to store the upper limit value and the lower limit value of the residual capacity measurement value set by the residual capacity limit value setter.

8. The power storage service system according to claim 2, wherein the second measurer comprises:

a third obtainer configured to obtain a time required for an additional operation of the residual capacity equalizer by using the self-discharge current difference, the residual capacity equalization current value, and the residual capacity, in a case that a sum of the self-discharge current value obtained from the second obtainer and the residual capacity equalization current value stored in the current value storage is positive; and

a fourth obtainer configured to obtain the residual time of the assembled battery system by using a limit range, the self-discharge current difference, the residual capacity equalization current value, and the residual capacity, in a case that the sum of the self-discharge current value and the residual capacity equalization current value is negative.

9. The power storage service system according to claim 8, wherein the second measurer comprises:

a battery state value output unit configured to output a current state value indicating that the self-discharge current difference is expanding if a ratio of an absolute value of the self-discharge current value to the residual capacity equalization current value is larger than or equal to a predetermined ratio.

10. The power storage service system according to claim 8, wherein the second measurer comprises:

a battery state value output unit configured to output a current state value indicating that the self-discharge current difference is normal if a ratio of an absolute value of the self-discharge current value to the residual capacity equalization current value is smaller than a predetermined ratio.

11. The power storage service system according to claim 8, wherein the second measurer comprises:

a battery state value output unit configured to output a current state value indicating that a non-stationary maintenance service is required if the residual time obtained by the fourth obtainer is less than a residual time until a predetermined maintenance service time.

12. The power storage service system according to claim 7, wherein the residual capacity limiter decreases a residual capacity lower limit value based on a setting of the residual time expanding signal for expanding a time until the effective SOC range of the assembled battery system is zero.

13. The power storage service system according to claim 7, wherein the residual capacity limiter increases a residual capacity upper limit value based on a setting of the residual time expanding signal for expanding a time until the effective SOC range of the assembled battery system is zero.

14. The power storage service system according to claim 9, further comprising:

a device configured to change either the residual capacity lower limit value or the residual capacity upper limit value, or both of the residual capacity lower limit value and the residual capacity upper limit value based on a residual time expanding signal for expanding a time until the effective SOC range of the assembled battery system is zero, to re-obtain the residual time and update a battery state value.

15. The power storage service system according to claim 1, further comprising:

a physical quantity measurer configured to measure a temperature of the unit cell if a ratio of the self-discharge current difference measured by the first measurer to the equalization current value is larger than or equal to a predetermined ratio; and

a first determiner configured to compare a temperature of the unit cell of which the self-discharge current difference is large with a temperature of the unit cell which is a criterion for obtaining the self-discharge current difference or an average temperature, to determine the temperature of the unit cell of which the self-discharge current difference is larger than the temperature of the unit cell which is the criterion or the average temperature, and to output a signal representing that a measurement of the self-discharge current difference is normal.

16. The power storage service system according to claim 1, wherein the first measurer comprises:

a physical quantity measurer configured to measure a dilatation of the external form of the unit cell if a ratio of the self-discharge current value to the equalization current value is larger than or equal to a predetermined ration;

a first determiner configured to compare a dilatation of the unit cell of which the self-discharge current difference is large with a dilatation of the unit cell which is a criterion for obtaining the self-discharge current difference or an average dilatation, to determine the dilatation of the unit cell of which the self-discharge current difference is larger than the dilatation of the unit cell which is the criterion or the average dilatation, and to output a signal representing that a measurement of the self-discharge current difference is normal.

17. The power storage service system according to claim 1, wherein the first measurer comprises a display configured to display a measurement result trend of the self-discharge current difference.

18. The power storage service system according to claim 9, further comprising:

a device configured to monitor remotely the current state value via a communication line including at least the internet.

19. The power storage service system according to claim 7, further comprising:

a maintenance service business system configured to provide a residual time expanding signal for expanding a time until the effective SOC range of the assembled battery system is zero to the residual capacity limit value setter by using the battery state value, the residual time, the self-discharge current difference, and a physical quantity which is a physical quantity for detecting an abnormal state of the unit cell, to plan a maintenance schedule of the assembled battery, and to implement a maintenance operation.