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

• US 9,599,674 B2
• Filed: 10/21/2016
• Issued: 03/21/2017
• 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:
  US15/299,915
• Publication Number:
  US 20170040809A1
• Time in Patent Office: 151 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, 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, and a controller for sending an on-command signal to the at least one electronic switch to turn on the electronic switch, and determining whether a switch failure detection process is executable based on a voltage of the electric storage device.

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; and

a controller for;

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

determining whether a switch failure detection process is executable based on a voltage of the electric storage device.

2. The switch failure detector according to claim 1, wherein the electric storage device comprises a plurality of electric storage devices, and

wherein the controller determines whether the switch failure detection process is executable based on voltages of the electric storage devices.

3. The switch failure detector according to claim 1, wherein the controller determines whether the switch failure detection process is executable based on the voltage of the electric storage device and a voltage proportional to a voltage across a load.

4. The switch failure detector according to claim 1, wherein the controller determines whether the electric storage device is in a discharging state, and sends an off-command signal to the electronic switch to turn off the electronic switch if the switch failure detection process is determined to be executable and the electric storage device is in the discharging state.

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; and

a controller for;

determining whether a switch failure detection process is executable based on a voltage of the electric storage device;

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

sending an off-command signal to the electronic switch to turn off the electronic switch if the switch failure detection process is determined to be executable and the electric storage device is in the discharging state.

6. The switch failure detector according to claim 5, wherein the electric storage device comprises a plurality of electric storage devices, and

wherein the controller determines whether the switch failure detection process is executable based on voltages of the electric storage devices.

7. The switch failure detector according to claim 5, wherein the controller determines whether the switch failure detection process is executable based on the voltage of the electric storage device and a voltage proportional to a voltage across a load.

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, 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 method comprising:

determining whether a switch failure detection process is executable based on a voltage of the electric storage device;

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

sending an off-command signal to the electronic switch to turn off the electronic switch if the switch failure detection process is determined to be executable and the electric storage device is in the discharging state.