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

• US 9,500,708 B2
• Filed: 06/10/2016
• Issued: 11/22/2016
• 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:
  US15/178,980
• Publication Number:
  US 20160282415A1
• Time in Patent Office: 165 Days
• Field of Search: 324/762.08, 324/762.09, 324/768, 324/769, 324/415, 324/416, 320/104, 320/112, 320/118, 320/128, 320/162, 320134-137, 320/163, 320/164, 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 detector configured to be installed in an electric system including an electric storage device, the switch failure detector includes at least one electronic switch connected in a path in which a charging current to the electric storage device and a discharging current from the electric storage device flow, at least one rectifier for passing 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 drop caused by the at least one electronic switch, and a controller for sending an on-command signal to the at least one electronic switch to turn on the electronic switch, and receiving the voltage detected by the switch voltage detection circuit while the on-command signal is sent to the electronic switch.

Claims

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

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

at least one rectifier for passing 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 drop caused by the at least one electronic switch; and

a controller for;

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

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

2. The switch failure detector according to claim 1, wherein the controller determines an input-output voltage of the at least one electronic switch based on the voltage.

3. The switch failure detector according to claim 2, wherein the controller determines whether the input-output voltage is lower than a reference voltage.

4. The switch failure detector according to claim 3, wherein the controller determines that a switch failure detection process is executable if the input-output voltage is lower than the reference voltage.

8. A battery pack, comprising:

an electric storage device; and

the switch failure detector according to claim 1.

10. An electric system, comprising:

an external device including a load; and

the battery pack according to claim 8,

wherein the electric storage device supplies power through the path to the load.

5. A switch failure detector configured to be installed in an electric system including an electric storage device, the switch failure detector comprising:

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

at least one rectifier for passing 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 for;

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

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

6. The switch failure detector according to claim 5, wherein the controller determines whether the input-output voltage is lower than a reference voltage.

7. The switch failure detector according to claim 6, wherein the controller determines that a switch failure detection process is executable if the input-output voltage is lower than the reference voltage.

9. A battery pack, comprising:

an electric storage device; and

the switch failure detector according to claim 5.

11. An electric system, comprising:

an external device including a load; and

the battery pack according to claim 9,

wherein the electric storage device supplies power through the path to the load.

12. A method of detecting a defect in an electric system including an electric storage device, an electronic switch, a rectifier, and a switch voltage detection circuit, 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 method comprising:

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

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

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

13. The method according to claim 12, further comprising:

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

14. The method according to claim 13, further comprising:

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

15. The method according to claim 14, further comprising:

determining that a switch failure detection process is executable if the input-output voltage is lower than the reference voltage.