Voltage detecting device, voltage detecting method, and battery pack system
AssigneeFujitsu Ten Limited
InventorsSho Tamura, Hiroyuki Fuji
Life of this patent
Estimating the term…
Abstract
A flying capacitor type voltage detecting device which uses a capacitor to detect a voltage of each battery stack of a battery pack which includes a plurality of battery stacks each of which includes a plurality of battery cells connected in series, includes: a detecting unit that detects a voltage between both ends of the capacitor, as the voltage of each battery stack; and a branch line that is a single line which is branched from a connection line connecting the battery stacks and the detecting unit and connected to the capacitor and where a current during charging of the capacitor and a current during discharging of the capacitor flow in opposite directions.
Claims6
A flying capacitor type voltage detecting device which uses a capacitor to detect a voltage of each battery stack of a battery pack which includes a plurality of battery stacks each of which includes a plurality of battery cells connected in series, comprising:
- a detecting unit that detects a voltage between both ends of the capacitor, as the voltage of each battery stack;
- a branch line that is a single line which is branched from a connection line connecting the battery stacks and the detecting unit and connected to the capacitor and where a current during charging of the capacitor and a current during discharging of the capacitor flow in opposite directions;
- a switching unit that is provided between the battery stacks and the capacitor;
- and
- a control unit that controls the switching unit,
- wherein the control unit includes:
- a charging-path selecting unit that selects a charging path including a battery stack to be subjected to voltage detection, the capacitor and the branch line, in a case of charging the capacitor, and
- a discharging-path selecting unit that selects a discharging path including a connection member electrically connecting two neighboring battery stacks of the plurality of battery stacks, the capacitor and the branch line in a case of discharging the capacitor.
A flying capacitor type voltage detecting method which uses a capacitor to detect a voltage of each battery stack of a battery pack which includes a plurality of battery stacks each of which includes a plurality of battery cells connected in series, comprising:
- charging the capacitor by making a current flow in a charging direction in a branch line which is a single line branched from a connection line connecting a detecting unit and each battery stack and connected to the capacitor;
- detecting a voltage between both ends of the capacitor as the voltage of each battery stack by the detecting unit;
- discharging the capacitor by making a current flow in the branch line in a discharging direction opposite to the charging direction;
- controlling to select a charging path including a battery stack to be subjected to voltage detection, the capacitor and the branch line, in a case of charging the capacitor;
- and
- controlling to select a discharging path including a connection member electrically connecting two neighboring battery stacks of the plurality of battery stacks, the capacitor and the branch line in a case of discharging the capacitor.
A battery pack system comprising:
- a battery pack that includes a plurality of battery stacks each of which includes a plurality of battery cells connected in series;
- and
- a flying capacitor type voltage detecting device that detects voltages of the battery stacks by the capacitor,
- wherein the voltage detecting device includes
- a detecting unit that detects a voltage between both ends of the capacitor, as the voltage of each battery stack;
- a branch line that is a single line which is branched from a connection line connecting each battery stack and the detecting unit and connected to the capacitor and where a current during charging of the capacitor and a current during discharging of the capacitor flow in opposite directions;
- and
- a switching unit that is provided between the battery stacks and the capacitor;
- and
- a control unit that controls the switching unit,
- wherein the control unit includes:
- a charging-path selecting unit that selects a charging path including a battery stack to be subjected to voltage detection, the capacitor and the branch line, in a case of charging the capacitor, and
- a discharging-path selecting unit that selects a discharging path including a connection member electrically connecting two neighboring battery stacks of the plurality of battery stacks, the capacitor and the branch line in a case of discharging the capacitor.
Dependencies are inferred from the claim text.