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

A switch failure detection device configured 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 drop caused by 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.

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 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 drop caused by 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.

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 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 drop caused by 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.