Voltage monitoring circuit, and vehicle equipped with same

• US 8,737,031 B2
• Filed: 08/28/2012
• Issued: 05/27/2014
• Est. Priority Date: 09/14/2011
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Ohnuki, Yasumichi
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): WILLOUGHBY, TERRENCE RONIQUE
• Application Number:
  US13/977,294
• Publication Number:
  US 20130279056A1
• Time in Patent Office: 637 Days
• Field of Search: None
• US Class Current: 361/86
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 58/19 Switching between serial connection and parallel connection of battery modules
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60L 58/30 for monitoring or controlling fuel cells
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: H02H 9/045 adapted to a particular application and not provided for elsewhere
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/00308 Overvoltage protection
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

During charging of a cell module in which a plurality of cells are connected in series, a voltage is applied in forward polarity to a switch element even when a current interrupting switch provided to the cell module is open, thereby shorting an anti-fuse element, and the switch element is thereby opened. A voltage monitoring circuit and a vehicle equipped with the voltage monitoring circuit are thereby provided in which a high voltage is not applied even when the cell module is charging when the current interrupting switch is open.

Claims

1. A voltage monitoring circuit for monitoring voltages across N chargeable and dischargeable series-connected cells of a battery module with a load being connected between a maximum potential and a minimum potential of the battery module, and a current blocking switch being connected between at least a pair of adjacent ones of the cells, wherein N+1 wires are connected from positive terminals and negative terminals of the cells to the voltage monitoring circuit, the voltage monitoring circuit comprising:

switching elements connected in series to respective ones of the N+1 wires apart from a wire carrying the maximum potential or the minimum potential, the switching elements being openable and closable by control signals from control lines branched from adjacent ones of the respective wires;

resistive elements connected in series respectively to the control lines between control input terminals of the switching elements and the adjacent ones of the respective wires; and

anti-fuse elements connected respectively between the control input terminals and the respective wires, the wires being disconnected and connected when the switching elements are opened and closed.

2. The voltage monitoring circuit according to claim 1, further comprising:

capacitors connected in parallel with the resistive elements, respectively.

3. The voltage monitoring circuit according to claim 1, wherein the switching elements comprise semiconductor switches that are closed when positive voltages are applied to the control input terminals;

and

the semiconductor switches are connected to the N wires apart from the wire carrying the maximum potential, and are closed by potentials of the control lines that are branched from adjacent wires of higher potentials.

4. The voltage monitoring circuit according to claim 1, wherein the switching elements comprise semiconductor switches that are closed when negative voltages are applied to the control input terminals;

and

the semiconductor switches are connected to the N wires apart from the wire carrying the minimum potential, and are closed by potentials of the control lines that are branched from adjacent wires of lower potentials.

5. The voltage monitoring circuit according to claim 1, wherein a charging unit for charging the battery module is connected between the maximum potential and the minimum potential of the battery module.

6. A vehicle incorporating:

a voltage monitoring circuit for monitoring voltages across N chargeable and dischargeable series-connected cells of a battery module with a load being connected between a maximum potential and a minimum potential of the battery module, and a current blocking switch being connected between at least a pair of adjacent ones of the cells, wherein N+1 wires are connected from positive terminals and negative terminals of the cells to the voltage monitoring circuit; and

a charging unit for charging the battery module and which is connected between the maximum potential and the minimum potential of the battery module,

wherein the voltage monitoring circuit comprising;

switching elements connected in series to respective ones of the N+1 wires apart from a wire carrying the maximum potential or the minimum potential, the switching elements being openable and closable by control signals from control lines branched from adjacent ones of the respective wires;

resistive elements connected in series respectively to the control lines between control input terminals of the switching elements and the adjacent ones of the respective wires; and

anti-fuse elements connected respectively between the control input terminals and the respective wires, the wires being disconnected and connected when the switching elements are opened and closed.