Switch failure detection device, battery pack including the same, and method of detecting failure of electronic switch

• US 9,121,907 B2
• Filed: 02/28/2013
• Issued: 09/01/2015
• Est. Priority Date: 03/01/2012
• Status: Active Grant

• Current Assignee: GS Yuasa International Ltd. (GS Yuasa Corporation)
• Original Assignee: GS Yuasa International Ltd. (GS Yuasa Corporation)
• Inventors: Shiraishi, Takeyuki, Itagaki, Takeshi
• Primary Examiner(s): Assouad, Patrick
• Assistant Examiner(s): CURTIS, SEAN M
• Application Number:
  US13/781,558
• Publication Number:
  US 20130229186A1
• Time in Patent Office: 915 Days
• Field of Search: 324/762.08, 324/762.09, 324/768, 324/769, 324/415, 324/416, 320/112, 320/118, 320/128, 320/162, 320/163, 320/164, 320/104, 320134-137, 307/85, 307/64, 361/90, 361/91.1
• US Class Current: 1/1
• CPC Class Codes: G01R 31/327 Testing of circuit interrupters, switches or circuit-breakers
• CPC Class Codes: G01R 31/3277 of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches
• CPC Class Codes: G01R 31/3278 of relays, solenoids or reed switches measuring contact resistance G01R27/205; high voltage magnetic switches G01R31/3271, G01R31/333; testing electric windings G01R31/72; monitoring of fail safe circuits H01H47/002
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A switch failure detection device includes a switch, a rectifier, a switch voltage detection circuit, and a controller. The switch is connected in a path in which a charging current to and a discharging current flow. The rectifier passes a discharging current by bypassing the switch when the switch is turned off. The detection circuit detects a voltage between an input and an output of the switch. The controller is configured to: determine whether the electric storage device is in a discharging state; send an off-command signal to the switch if the electric storage device is in the discharging state; receive the voltage; determine an input-output voltage of the switch based on the voltage; determine whether the input-output voltage is lower than a first reference voltage; and determine the switch has a turn-off problem if the input-output voltage is lower than the first reference voltage.

Claims

1. A switch failure detection device to be installed in an electric system including an electric storage device, the switch failure detection device comprising:

at least one electronic switch to be connected in a path in which a charging current to the electric storage device and a discharging current from the electric storage device flow, the at least one electronic switch including a first electronic switch;

at least one rectifier for passing a discharging current by bypassing the electronic switch when the electronic switch is turned off, the at least one rectifier including a first rectifier being connected parallel to or being parasitic to the first electronic switch such that a forward direction thereof corresponds to a direction in which the discharging current flows;

a switch voltage detection circuit configured to detect a voltage between an input and

an output of the at least one electronic switch; and

a controller for;

determining whether the electric storage device is in a discharging state;

sending an off-command signal to the first electronic switch to turn off the first electronic switch if the electric storage device is in the discharging state;

receiving the voltage detected by the switch voltage detection circuit while the off-command signal is sent to the first electronic switch;

determining an input-output voltage of the at least one electronic switch based on the voltage;

determining whether the input-output voltage is lower than a reference voltage;

and determining the first electronic switch has a turn-off problem in which the first electronic switch does not turn off according to the off-command signal if the input-output voltage is lower than the reference voltage.

2. The switch failure detection device according to claim 1,

wherein the voltage detected by the switch voltage detection circuit includes an on voltage and an off voltage, the on voltage being a voltage between the input and the output of the at least one electronic switch detected while an on-command signal to turn on the first electronic switch is sent to the first electronic switch, the off voltage being a voltage between the input and the output of the at least one electronic switch detected while the off-command

signal is sent to the first electronic switch, and

wherein the controller:

sends the on-command signal to the first electronic switch to turn on the first electronic switch; and

receives the on voltage detected by the switch voltage detection circuit while the on-command signal is sent to the first electronic switch.

3. The switch failure detection device according to claim 2, wherein the controller determines the input-output voltage of the at least one electronic switch based on a difference between the on voltage and the off voltage.

4. The switch failure detection device according to claim 2,

wherein the reference voltage is a first reference voltage, and

wherein the controller:

determines whether the on voltage is lower than a second reference voltage;

and cancels the determining, whether the voltage is lower than the first reference voltage, if the on voltage is higher than the second reference voltage.

5. The switch failure detection device according to claim 1,

wherein the at least one electronic switch further includes a second electronic switch,

wherein the at least one rectifier further includes a second rectifier being connected parallel to or being parasitic to the second electronic switch such that a forward direction thereof corresponds to a direction in which the charging current flows,

wherein the switch voltage detection circuit is further configured to detect a first voltage between an input and an output of the first electronic switch and a second voltage between an input and an output of the second electronic switch,

wherein the reference voltage is a first reference voltage, and

wherein the controller:

sends the off-command signal to the first electronic switch and an on-command

signal to the second electronic switch to turn on the second electronic switch if the electric storage device is in the discharging state;

sends an on-command signal to the first electronic switch to turn on the first electronic switch and an off-command signal to the second electronic switch if the electric storage device is in the charging state;

receives the first voltage detected by the switch voltage detection circuit while the off-command signal is sent to the first electronic switch;

determines a first input-output voltage based on the first voltage;

determines whether the first input-output voltage is lower than the first reference voltage;

determines the first electronic switch has a turn-off problem in which the first electronic switch is not turned off according to the off-command signal sent to the first electronic switch if the first input-output voltage is lower than the first reference voltage;

receives the second voltage detected by the switch voltage detection circuit while the off-command signal is sent to the second electronic switch;

determines a second input-output voltage based on the second voltage;

determines whether the second input-output voltage is lower than the first reference voltage; and

determines the second electronic switch has a turn-off problem in which the second electronic switch is not turned off according to the off-command signal sent to the second electronic switch if the second input-output voltage is lower than the first reference voltage.

11. A battery pack, comprising:

an electric storage device; and

the switch failure detection device according to claim 1.

15. The switch failure detection device according to claim 1,

wherein the first rectifier is parasitic to the first electronic switch.

16. The switch failure detection device according to claim 15,

wherein the at least one electronic switch further includes a second electronic switch, and

wherein the at least one rectifier further includes a second rectifier, the second rectifier being parasitic to the second electronic switch such that a forward direction thereof corresponds to a direction in which the charging current flows.

17. The switch failure detection device according to claim 1,

wherein the at least one electronic switch further includes a second electronic switch, and

wherein the at least one rectifier includes a second rectifier being parasitic to the second electronic switch such that a forward direction thereof corresponds to a direction in which the charging current flows.

18. The switch failure detection device according to claim 17,

wherein the switch voltage detection circuit is further configured to detect a voltage between an input and an output of the first electronic switch and a second voltage between an input and an output of the second electronic switch.

6. A switch failure detection device to be installed in an electric system including an electric storage device, the switch failure detection device comprising:

at least one electronic switch to be connected in a path in which a charging current to the electric storage device and a discharging current from the electric storage device flow, the at least one electronic switch including a first electronic switch;

at least one rectifier for passing a charging current by bypassing the electronic switch when the electronic switch is turned off, the at least one rectifier including a first rectifier being connected parallel to or being parasitic to the first electronic switch such that a forward direction thereof corresponds to a direction in which the charging current flows;

a switch voltage detection circuit configured to detect a voltage between an input and

an output of the at least one electronic switch; and

a controller for;

determining whether the electric storage device is in a charging state;

sending an off-command signal to the first electronic switch to turn off the first electronic switch if the electric storage device is in the charging state;

receiving the voltage detected by the switch voltage detection circuit while the off-command signal is sent to the first electronic switch;

determining an input-output voltage of the at least one electronic switch based on the voltage;

determining whether the input-output voltage is lower than a reference voltage;

and determining the first electronic switch has a turn-off problem in which the first electronic switch does not turn off according to the off-command signal if the input-output voltage is lower than the reference voltage.

7. The switch failure detection device according to claim 6,

wherein the voltage detected by the switch voltage detection circuit includes an on voltage and an off voltage, the on voltage being a voltage between the input and the output of the at least one electronic switch detected while an on-command signal to turn on the first electronic switch is sent to the first electronic switch, the off voltage being a voltage between the input and the output of the at least one electronic switch detected while the off-command

signal is sent to the first electronic switch, and

wherein the controller:

sends the on-command signal to the first electronic switch to turn on the first electronic switch; and

receives the on voltage detected by the switch voltage detection circuit while the on-command signal is sent to the first electronic switch.

8. The switch failure detection device according to claim 7, wherein the controller determines the input-output voltage of the at least one electronic switch based on a difference between the on voltage and the off voltage.

9. The switch failure detection device according to claim 7,

wherein the reference voltage is a first reference voltage, and

wherein the controller:

determines whether the on voltage is lower than a second reference voltage;

and cancels the determining, whether the voltage is lower than the first reference voltage, if the on voltage is higher than the second reference voltage.

10. The switch failure detection device according to claim 6,

wherein the at least one electronic switch further includes a second electronic switch,

wherein the at least one rectifier further includes a second rectifier, the second rectifier being connected parallel to or being parasitic to the second electronic switch such that a forward direction thereof corresponds to a direction in which the discharging current flows,

wherein the switch voltage detection circuit is further configured to detect a first voltage between an input and an output of the first electronic switch and a second voltage between an input and an output of the second electronic switch,

wherein the reference voltage is a first reference voltage, and

wherein the controller:

sends an off-command signal to the first electronic switch and an on-command

signal to the second electronic switch to turn on the second electronic switch if the electric storage device is in the charging state;

sends an on-command signal to the first electronic switch to turn on the first electronic switch and the off-command signal to the second electronic switch if the electric storage device is in the discharging state;

receives the first voltage detected by the switch voltage detection circuit while the off-command signal is sent to the second electronic switch;

determines a first input-output voltage based on the first voltage;

determines whether the first input-output voltage is lower than the first reference voltage;

determines the second electronic switch has a turn-off problem in which the second electronic switch is not turned off according to the off-command signal sent to the second electronic switch if the first input-output voltage is lower than the first reference voltage;

receives the second voltage detected by the switch voltage detection circuit while the off-command signal is sent to the first electronic switch;

determines a second input-output voltage based on the second voltage;

determines whether the second input-output voltage is lower than the first reference voltage; and

determines the first electronic switch has a turn-off problem in which the first electronic switch is not turned off according to the off-command signal sent to the first electronic switch if the second input-output voltage is lower than the first reference voltage.

12. A battery pack, comprising:

an electric storage device; and

the switch failure detection device according to claim 6.

13. A method of detecting a failure of an electronic switch in an electric system including an electric storage device, the electronic switch, and a rectifier, the electronic switch being connected in a path in which a charging current to the electric storage device and a discharging current from the electric storage device flow, the rectifier being configured to pass a discharging current by bypassing the electronic switch when the electronic switch is turned off, the rectifier being connected parallel to or being parasitic to the electronic switch such that a forward direction thereof corresponds to a direction in which the discharging current flows, the method comprising:

determining whether the electric storage device is in a discharging state;

sending an off-command signal to the electronic switch to turn off the electronic switch if the electric storage device is in the discharging state;

detecting a voltage between an input and an output of the electronic switch while the off-command signal is sent to the electronic switch;

determining an input-output voltage of the electronic switch based on the detected voltage;

determining whether the input-output voltage is lower than a reference voltage; and

determining the electronic switch has a problem in which the switch does not turn off according to the off-command signal if the input-output voltage is lower than the reference voltage.

14. A method of detecting a failure of an electronic switch in an electric system including an electric storage device, the electronic switch, and a rectifier, the electronic switch being connected in a path in which a charging current to the electric storage device and a discharging current from the electric storage device flow, the rectifier being configured to pass a charging current by bypassing the electronic switch when the electronic switch is turned off, the rectifier being connected parallel to or being parasitic to the electronic switch such that a forward direction thereof corresponds to a direction in which the charging current flows, the method comprising:

determining whether the electric storage device is in a charging state;

sending an off-command signal to the electronic switch to turn off the electronic switch if the electric storage device is in the charging state;

detecting a voltage between an input and an output of the electronic switch while the off-command signal is sent to the electronic switch;

determining an input-output voltage of the electronic switch based on the detected voltage;

determining whether the input-output voltage is lower than a reference voltage; and

determining the electronic switch has a problem in which the switch does not turn off according to the off-command signal if the input-output voltage is lower than the reference voltage.