Power supply apparatus, protection apparatus, and protection method

A power supply apparatus comprising:

• a plurality of battery modules that each include a battery and a switch and that are connected in parallel to each other;
• a voltage detecting unit that detects a voltage of each of the batteries;
• and
• a controlling unit that
• when the voltage detected by the voltage detecting unit is equal to or greater than a first threshold, determines that a voltage detection line between a focused-on battery and the voltage detecting unit has been broken,
• when the voltage detected by the voltage detecting unit is less than the first threshold and is equal to or greater than a second threshold that is less than the first threshold, determines that the focused-on battery has been overcharged,
• when the voltage detected by the voltage detecting unit is equal to or less than a third threshold that is less than the second threshold, and is equal to or greater than a fourth threshold that is less than the third threshold, determines that the focused-on battery has been overdischarged,
• when the voltage detected by the voltage detecting unit is less than the fourth threshold, determines that the voltage detection line between the focused-on battery and the voltage detecting unit has been broken,
• when the controlling unit has determined that the voltage detection line between the focused-on battery and the voltage detecting unit has been broken, controls operations of each of the switches so as to separate a battery module that includes the voltage detection line from the power supply apparatus, and
• when the controlling unit has determined that the focused-on battery has been overcharged or overdischarged, limits power input to, or output from, every battery module.

A protection apparatus that protects a power supply apparatus that includes a plurality of battery modules that each include a battery and a switch, by separating, from the power supply apparatus, a battery module in which an abnormality has occurred from among the plurality of battery modules, the protection apparatus comprising:

• a voltage detecting unit that detects a voltage of each of the batteries;
• and
• a controlling unit that
• when the voltage detected by the voltage detecting unit is equal to or greater than a first threshold, determines that a voltage detection line between a focused-on battery and the voltage detecting unit has been broken,
• when the voltage detected by the voltage detecting unit is less than the first threshold and is equal to or greater than a second threshold that is less than the first threshold, determines that the focused-on battery has been overcharged,
• when the voltage detected by the voltage detecting unit is equal to or less than a third threshold that is less than the second threshold, and is equal to or greater than a fourth threshold that is less than the third threshold, determines that the focused-on battery has been overdischarged,
• when the voltage detected by the voltage detecting unit is less than the fourth threshold, determines that the voltage detection line between the focused-on battery and the voltage detecting unit has been broken,
• when the controlling unit has determined that the voltage detection line between the focused-on battery and the voltage detecting unit has been broken, controls operations of each of the switches so as to separate a battery module that includes the voltage detection line from the power supply apparatus, and
• when the controlling unit has determined that the focused-on battery has been overcharged or overdischarged, limits power input to, or output from, every battery module.

A protection method for protecting a power supply apparatus that includes a plurality of battery modules that each include a battery and a switch, by separating, from the power supply apparatus, a battery module in which an abnormality has occurred from among the plurality of battery modules, the protection method comprising:

• by using a controlling unit that controls operations of the switches, and when a voltage detected by a voltage detecting unit is equal to or greater than a first threshold, determining that a voltage detection line between a focused-on battery and the voltage detecting unit has been broken;
• by using the controlling unit, and when the voltage detected by the voltage detecting unit is less than the first threshold and is equal to or greater than a second threshold that is less than the first threshold, determining that the focused-on battery has been overcharged,
• by using the controlling unit, and when the voltage detected by the voltage detecting unit is equal to or less than a third threshold that is less than the second threshold, and is equal to or greater than a fourth threshold that is less than the third threshold, determining that the focused-on battery has been overdischarged;
• by using the controlling unit, and when the voltage detected by the voltage detecting unit is less than the fourth threshold, determining that a voltage detection line between the focused-on battery and the voltage detecting unit has been broken;
• by using the controlling unit, and when the controlling unit has determined that the voltage detection line between the focused-on battery and the voltage detecting unit has been broken, controlling operations of each of the switches so as to separate a battery module that includes the voltage detection line from the power supply apparatus;
• and
• by using the controlling unit, and when the controlling unit has determined that the focused-on battery has been overcharged or overdischarged, limiting power input to, or output from, every battery module.