Denso Ten Limited

Fujitsu Ten Limited

Atsushi Izutani

Yoshihiro Nakao

Takehito Iwanaga

Kazuya Ogawa

Akihito Kondo

A failure detection apparatus includes: a first switch configured to be connected to a positive electrode of a battery; a second switch configured to be connected to a negative electrode of the battery; detection resistances that are connected in series between the first switch and the second switch; and a measurement circuit that measures a voltage of the detection resistances, wherein (i) both the first switch and the second switch are turned on to form a failure-detection series-connected circuit consisting of the battery and the detection resistances, and (ii) a failure detection mode is provided to detect a failure based on the voltage measured by the measurement circuit.

Failure detection apparatus

A battery voltage measurement circuit includes: a first switch configured to be connected to a positive electrode of a battery; a second switch configured to be connected to a negative electrode of the battery; detection resistances that are connected in series between the first switch and the second switch; capacitors that are connected in parallel to the detection resistances; and a measurement circuit that measures a voltage applied to the detection resistances. The battery voltage measurement circuit has a plurality of measurement modes depending upon status of the first and second switches, and further has a failure detection mode for the capacitors based on a change in the voltage after switching from one to an other of the measurement modes.

Battery voltage measurement circuit

An insulation resistance detection apparatus includes: a first switch connected to a high potential side of a battery assembly including plural battery cells connected in series; a second switch connected to a low potential side of the battery assembly; a detection resistor; a controller configured to turn on one of the first switch and the second switch and turn off the other of the first switch and the second switch to form a series connection circuit including the battery assembly, an insulation resistor of the battery assembly, and the detection resistor, and calculate insulation resistance based on a voltage applied to the detection resistor, in which the first switch is connected between two battery cells on the high potential side among the plural battery cells.

Insulation resistance detection apparatus

A controller (1) forms an insulation measurement path and turns on a third switch connected in parallel to a capacitor, (2) after a lapse of a first time period turns off the third switch, and (3) detects an insulation abnormality based on a voltage of the capacitor measured after a lapse of a second time period after the turning off of the third switch.

Insulation abnormality detection apparatus

A voltage detection device includes battery stacks, and a connection member configured to electrically connect the battery stacks. The voltage detection device includes: a capacitor connected to each battery stack in parallel; switches, each of which having one end connected to a terminal of each battery stack and the other end connected to the capacitor; a detection unit configured to detect a voltage of the capacitor, and a control unit configured to control the switches, in which the control unit comprises: a discharging path selection unit that selects a discharging path comprising the connection member and the capacitor when discharging the capacitor, and a determination unit configured to determine whether an abnormality has occurred in the battery pack or at least one of the switches, in correspondence to at least one of a voltage of the capacitor after charging and a voltage of the capacitor after discharging.

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Kobe, Japan

Atsushi Izutani