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

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.

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.

8. A battery pack, comprising:

an electric storage device; and

the switch failure detector according to claim 1 .

9. A battery pack, comprising:

an electric storage device; and

the switch failure detector according to claim 5 .

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.

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.