SWITCH FAILURE DETECTION DEVICE, BATTERY PACK INCLUDING THE SAME, AND METHOD OF DETECTING FAILURE OF ELECTRONIC SWITCH

• US 20130229186A1
• Filed: 02/28/2013
• Published: 09/05/2013
• 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
• Granted Patent: US 9,121,907 B2
• Time in Patent Office: Days
• US Class Current: 324/415
• 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 and switched between on and off;

at least one rectifier configured to pass a discharging current by bypassing the electronic switch when the electronic switch is turned off;

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 configured to;

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

send an off-command signal to the at least one electronic switch to turn off the at least one electronic switch if the electric storage device is in the discharging state;

receive the voltage detected by the switch voltage detection circuit while the off-command signal is sent to the at least one electronic switch;

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

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

determine the at least one electronic switch has a turn-off problem in which the at least one 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 at least one electronic switch is sent to the at least one 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 at least one electronic switch, and

the controller is further configured to:

send an on-command signal to the at least one electronic switch to turn on the at least one electronic switch; and

receive the on voltage detected by the switch voltage detection circuit while the on-command signal is sent to the at least one electronic switch.

3. The switch failure detection device according to claim 2, wherein the controller is further configured to determine 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

the controller is further configured to:

determine whether the on voltage is lower than a second reference voltage; and

cancel 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 includes a first electronic switch and a second electronic switch,

the at least one rectifier includes a first rectifier and a second rectifier, the first rectifier being connected parallel to the first electronic switch such that a forward direction thereof corresponds to a direction in which the discharging current flows, the second rectifier being connected parallel to the second electronic switch such that a forward direction thereof corresponds to a direction in which the charging current flows,

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,

the reference voltage is a first reference voltage, and

the controller is further configured to:

send 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;

send 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 charging state;

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

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

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

determine 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;

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

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

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

determine 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.

6. The switch failure detection device according to claim 1, wherein

the at least one electronic switch includes a first electronic switch and a second electronic switch,

the at least one rectifier includes a first rectifier and a second rectifier, the first rectifier being parasitic to the first electronic switch such that a forward direction thereof corresponds to a direction in which the discharging current flows, 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,

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,

the reference voltage is the first reference voltage, and

the controller is further configured to:

send 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;

send 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 charging state;

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

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

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

determine 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;

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

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

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

determine 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.

13. A battery pack comprising:

an electric storage device; and

the switch failure detection device according to claim 1.

7. 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 and a discharging current flow and switched between on and off;

at least one rectifier configured to pass a charging current by bypassing the electronic switch when the electronic switch is turned off;

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 configured to;

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

send an off-command signal to the at least one electronic switch to turn off the at least one electronic switch if the electric storage device is in the charging state;

receive the voltage detected by the switch voltage detection circuit while the off-command signal is sent to the at least one electronic switch;

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

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

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

8. The switch failure detection device according to claim 7, 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 at least one electronic switch is sent to the at least one 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 at least one the electronic switch, and

the controller is further configured to:

send an on-command signal to the at least one electronic switch to turn on the at least one electronic switch; and

receive the on voltage detected by the switch voltage detection circuit while the on-command signal is sent to the at least one electronic switch.

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

10. The switch failure detection device according to claim 8, wherein

the reference voltage is a first reference voltage, and

the controller is further configured to:

determine whether the on voltage is lower than a second reference voltage; and

cancel the determining whether the voltage is lower than the first reference voltage if the on voltage is higher than the second reference voltage.

11. The switch failure detection device according to claim 7, wherein

the at least one electronic switch includes a first electronic switch and a second electronic switch,

the at least one rectifier includes a first rectifier and a second rectifier, the first rectifier being connected parallel to the first electronic switch such that a forward direction thereof corresponds to a direction in which the discharging current flows, the second rectifier being connected parallel to the second electronic switch such that a forward direction thereof corresponds to a direction in which the charging current flows,

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,

the reference voltage is a first reference voltage, and

the controller is further configured to:

send 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;

send 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 charging state;

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

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

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

determine 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;

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

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

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

determine 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.

12. The switch failure detection device according to claim 7, wherein

the at least one electronic switch includes a first electronic switch and a second electronic switch,

the at least one rectifier includes a first rectifier and a second rectifier, the first rectifier being parasitic to the first electronic switch such that a forward direction thereof corresponds to a direction in which the discharging current flows, 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,

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,

the reference voltage is a first reference voltage, and

the controller is further configured to:

send 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;

send 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 charging state;

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

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

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

determine 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;

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

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

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

determine 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.

14. A battery pack comprising:

an electric storage device; and

the switch failure detection device according to claim 7.

15. 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 and being switched between on and off, the rectifier being configured to pass a discharging current by bypassing the electronic switch when the electronic switch is turned off, 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 dose not turn off according to the off-command signal if the input-output voltage is lower than the reference voltage.

16. 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 and being switched between on and off, the rectifier being configured to pass a charging current by bypassing the electronic switch when the electronic switch is turned off, 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 dose not turn off according to the off-command signal if the input-output voltage is lower than the reference voltage.