VOLTAGE MONITORING SYSTEM AND VOLTAGE MONITORING MODULE

• US 20120306506A1
• Filed: 05/27/2012
• Published: 12/06/2012
• Est. Priority Date: 05/31/2011
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: KIUCHI, Hideki
• Granted Patent: US 8,988,078 B2
• Time in Patent Office: Days
• US Class Current: 324/434
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• 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 10/48 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: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• 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

In a voltage monitoring system, a voltage monitoring module includes an adjusting current control circuit to generate an adjusting current so that the operating current consumed by the voltage monitoring modules reaches a specified value corresponding to a first operation current setting command, and stops generating the adjusting current according to an operating current switching command; and an operating current measurement circuit to measure the operating current according to the operating current measuring command following the operating current switching command; and in which a module control circuit sends a second operation current setting command based on the operating current that was measured, and the adjusting current control circuit generates an adjusting current so that the operating current reaches a specified value corresponding to the second operating current setting command.

Claims

1. A voltage monitoring system to monitor a plurality of battery cells mutually coupled in series, comprising:

a voltage monitoring module configured to operate on a voltage received from at least one battery cell among a plurality of battery cells and to monitor the battery cells; and

a module control circuit configured to control the voltage monitoring module,

wherein the voltage monitoring module includes;

an adjusting current control circuit that generates an adjusting current in response to a first operating current setting command sent from the module control circuit so that an operating current consumed by the voltage monitoring module reaches a specified value corresponding to the first operating current setting command and stops generating of the adjusting current in response to an operating current switching command sent from the module control circuit; and

an operating current measurement circuit that measures the operating current in response to an operating current measuring command sent following the operating current switching command,

wherein the module control circuit sends a second operating current setting command based on the measured operating current, and

wherein the adjusting current control circuit generates an adjusting current in response to the second operating current setting command so that the operating current reaches a specified value corresponding to the second operating current setting command.

2. The voltage monitoring system according to claim 1,

wherein the adjusting current control circuit generates an adjusting current so that the sum of the adjusting current and the load current consumed by circuits within the voltage monitoring module other than the adjusting current control circuit attains a specified value corresponding to the first or the second operating current setting command.

3. The voltage monitoring system according to claim 1,

wherein the adjusting current control circuit includes a variable resistor capable of switching the resistance values, selects a resistance value according to the first or second operating current setting command, and generates an adjusting current.

4. The voltage monitoring system according to claim 1 comprising:

a plurality of the voltage monitoring modules,

wherein the module control circuit obtains a current measurement value showing the size of the operating current from the respective voltage monitoring modules, and

generates the second operating current setting command corresponding to a current value larger than the current measurement value showing the largest value among the obtained current setting values.

5. The voltage monitoring system according to claim 4,

wherein the voltage monitoring modules each has a specific ID to identify itself, and

wherein the module control circuit specifies any one of the voltage monitoring modules based on the specific IDs, and sends the first operating current setting command and the second operating current setting command to each of the specified voltage monitoring modules.

6. The voltage monitoring system according to claim 1,

wherein the module control circuit includes:

a timer configured to measure the elapsed time, and

wherein the module control circuit sends the operating current switching command when the time measured on the timer has reached a specified time.

7. The voltage monitoring system according to claim 1,

wherein the module control circuit sends a third operating current setting command to set the operating current to a preset sleep current value after stopping the voltage monitoring operation for the battery cell voltage by the voltage monitoring module, and

wherein the adjusting current control circuit generates an adjusting current in response to the third operating current setting command so that the operating current reaches a specified value according to the third operating current setting command.

8. The voltage monitoring system according to claim 1,

wherein the voltage monitoring module includes:

a communication circuit configured to communicate with the module control circuit or other voltage monitoring modules; and

a register configured to store the values specified by the first or second operating current setting command.

9. The voltage monitoring system according to claim 1,

wherein the operating current includes a current consumed in other circuits installed outside of the voltage monitoring modules.

10. The voltage monitoring system according to claim 1,

wherein the adjusting current control circuit includes:

a current consumption circuit configured to consume the adjusting current and to increase or decrease the adjusting current in a direction opposite the increase or decrease in the load circuit, and

a current setting circuit configured to generate a reference current to serve as a reference for the size of the operating current,

wherein the current setting circuit switches the size of the reference current according to the value shown by the first and second operating current setting commands.

11. The voltage monitoring system according to claim 1,

wherein the voltage monitoring module further includes:

a regulator circuit configured to convert the voltage supplied from the battery cell and to generate an internal voltage supplied to circuits inside the voltage monitoring module.

12. The voltage monitoring system according to claim 11,

wherein the regulator circuit includes:

an output transistor whose source is coupled to the power supply terminal, and whose drain is coupled to the output terminal; and

a first resistor and a second resistor coupled between the output terminal and the ground terminal,

wherein the regulator circuit generates an internal voltage by increasing or decreasing a reference voltage based on the resistance ratio of the first resistor to the second resistor,

wherein the adjusting current control circuit includes;

a current setting transistor coupled by a current mirror coupling to the output transistor; and

a current setting resistor coupled between the drain of the current setting transistor and the ground terminal,

wherein the adjusting current control circuit switches the resistance values of the current setting resistor based on values shown in the first and second operating current setting command, and generates a reference current based on the reference voltage and resistance value of the current setting resistor, and

wherein the regulator circuit increases or decreases the current flowing in the output transistor based on the reference voltage.

13. The voltage monitoring system according to claim 11,

wherein the regulator circuit includes:

an output transistor whose drain is coupled to the power supply terminal and whose source is coupled to the output terminal; and

a first resister and a second resister coupled between the output terminal and the ground terminal,

wherein the regulator circuit generates an internal voltage by increasing or decreasing a reference voltage based on the resistance ratio between a first resistor and a second resistor,

wherein the adjusting current control circuit includes;

a first transistor coupled between the drain of the output transistor and the power supply terminal, and a second transistor coupled by a current mirror coupling to the first transistor; and

a current setting resistor coupled between the drain of the second transistor and the ground terminal,

wherein the adjusting current control circuit switches the resistance values of the current setting resistor based on values shown in the first and second operating current setting command, and generate a reference current based on the reference voltage and resistance value of the current setting resistor, and

wherein the regulator circuit increases or decreases the current value of the current flowing in the output transistor based on the reference current.

14. A voltage monitoring module to operate on the voltage received from at least one battery cell among a plurality of battery cells mutually coupled in series and to monitor the battery cells, the voltage monitoring module comprising:

an adjusting current control circuit that generates an adjusting current in response to a first operating current setting command sent from outside section so that the operating current consumed by the voltage monitoring module reaches a specified value corresponding to the first operating current setting command and stops generating of the adjusting current in response to an operating current switching command sent from the outside section; and

an operating current measurement circuit that measures the operating current according to the operating current measuring command sent following the operating current switching command from an outside section,

wherein the adjusting current control circuit generates an adjusting current in response to a second operating current setting command generated based on the measured operating current so that the operating current reaches a specified value corresponding to the second operating current setting command.

15. The voltage monitoring module according to claim 14,

wherein the adjusting current control circuit generates an adjusting current so that the sum of the adjusting current and the load current consumed by circuits within the voltage monitoring module other than the adjusting current control circuit attains a specified value corresponding to the first or the second operating current setting command.

16. The voltage monitoring module according to claim 14,

wherein the adjusting current control circuit includes a variable resistor capable of switching the resistance values, selects a resistance value according to the first and second operating current setting command, and generates an adjusting current.

17. The voltage monitoring module according to claim 14, comprising:

a communication circuit configured to communicate with the module control circuit that controls the voltage monitoring module or other voltage monitoring modules; and

a register configured to store the values specified by the first or second operating current setting command.

18. The voltage monitoring module according to claim 14,

wherein the first and second operating current setting commands specify a current value that is the same or greater than the maximum value of operating current measured in the voltage monitoring modules.

19. The voltage monitoring module according to claim 14,

wherein the size of the adjusting current is rewritten at specified intervals.

20. The voltage monitoring module according to claim 14,

wherein the adjusting current control circuit includes:

a current consumption circuit configured to consume the adjusting current and to increase or decrease the adjusting current in a direction opposite the increase or decrease in the load circuit, and

a current setting circuit configured to generate a reference current to serve as a reference for the size of the operating current,

wherein the current setting circuit switches the size of the reference current according to the value shown by the first and second operating current setting commands.

21. The voltage monitoring module according to claim 14, further comprising:

a regulator circuit configured to convert the voltage supplied from the battery cell and to generate an internal voltage supplied to circuits inside the voltage monitoring module.

22. The voltage monitoring module according to claim 21,

wherein the regulator circuit includes:

an output transistor whose source is coupled to the power supply terminal, and whose drain is coupled to the output terminal; and

a first resistor and a second resistor coupled between the output terminal and the ground terminal, and

wherein the regulator circuit generates the internal voltage by increasing or decreasing a reference voltage based on the resistance ratio between the first resistor and the second resistor, and

wherein the adjusting current control circuit includes;

a current setting transistor coupled by a current mirror coupling to the output transistor; and

a current setting resistor coupled between the drain of the current setting transistor and the ground terminal, and

wherein the adjusting current control circuit switches the resistance values of the current setting resistor based on values shown in the first and second operating current setting command, and generates a reference current based on the reference voltage and resistance value of the current setting resistor, and

wherein the regulator circuit increases or decreases the current flowing in the output transistor based on the reference voltage.

23. The voltage monitoring module according to claim 21,

wherein the regulator circuit includes:

an output transistor whose drain is coupled to the power supply terminal and whose source is coupled to the output terminal; and

a first resistor and a second resistor coupled between the output terminal and the ground terminal, and

wherein the regulator circuit generates the internal voltage by increasing or decreasing a reference voltage based on the resistance ratio between the first resistor and the second resistor, and

wherein the adjusting current control circuit includes;

a first transistor coupled between the drain of the output transistor and the power supply terminal, and a second transistor coupled by current mirror coupling to the first transistor; and

a current setting resistor coupled between the drain of the second transistor and the ground terminal, and

wherein the adjusting current control circuit switches the resistance values of the current setting resistor based on values shown in the first and second operating current setting command, and generates a reference current based on the reference voltage and resistance value of the current setting resistor, and

wherein the regulator circuit increases or decreases the current value of the current flowing in the output transistor based on the reference current.