Battery system monitoring apparatus and electric storage device including the same

• US 10,454,283 B2
• Filed: 05/16/2017
• Issued: 10/22/2019
• Est. Priority Date: 10/20/2011
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Kudo, Akihiko, Kikuchi, Mutsumi, Emori, Akihiko
• Primary Examiner(s): Grant, Robert
• Assistant Examiner(s): Trischler, John T
• Application Number:
  US15/596,700
• Publication Number:
  US 20170250545A1
• Time in Patent Office: 889 Days
• Field of Search: 320118
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• 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 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02M 7/44 by static converters
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

A battery system monitoring apparatus for monitoring a cell group having a plurality of battery cells, and includes a cell controller IC which monitors and controls the states of the plurality of battery cells. A battery controller controls the cell controller IC and a plurality of voltage detection lines measure the voltage across the terminals of the battery cell. The voltage detection lines connect positive and negative electrodes of the battery cell, respectively, to a plurality of voltage input terminals of the cell controller IC. A power line connects the positive electrode of the battery cell having the highest potential among the plurality of battery cells to a power supply terminal of the cell controller IC and a ground line which connects the negative electrode of the battery cell having the lowest potential among the plurality of battery cells to a ground terminal of the cell controller IC.

Claims

1. A battery system monitoring apparatus for monitoring a plurality of battery cells connected in series, the battery system monitoring apparatus comprising:

a cell controller integrated circuit (IC) that monitors and controls discharge of the plurality of battery cells, the cell controller IC including a power supply terminal, a ground terminal, a plurality of balancing switches and a plurality of cell voltage inputs;

a power line circuit that includes;

a power line that connects a positive electrode of a first battery cell that has a highest potential among the plurality of battery cells to the power supply terminal,

a first input resistor that is connected in series between the positive electrode of the first battery cell and a first cell voltage input from the plurality of cell voltage inputs, wherein the first input resistor is connected to the first cell voltage input via a first wire,

a first capacitor that is connected to the first wire and a midpoint potential voltage detection line, and

a first balance line that is connected to the power line, the positive electrode of the first battery cell and a first balance switch from the plurality of balancing switches;

a ground line circuit that includes;

a ground line that connects a negative electrode of a last battery cell that has a lowest potential among the plurality of battery cells to the ground terminal,

a last input resistor that is connected in series between the negative electrode of the last battery cell and a last cell voltage input from the plurality of cell voltage inputs, wherein the last input resistor is connected to the last cell voltage input via a last wire,

a last capacitor that is connected to the ground line and the midpoint potential voltage detection line, and

a last balance line that is connected to the negative electrode of the last cell, the last input resistor and a last balance switch from the plurality of balancing switches, wherein the last balance includes a last balancing resistor between the negative electrode and the last balance switch; and

a plurality of RC circuits that are each connected to a respective battery cell from the plurality of battery cells other than the first cell and the last cell, wherein each respective RC circuit from the plurality of RC circuits includes;

a respective input resistor that is connected in series between a positive terminal of the respective battery cell and a respective cell voltage input from the plurality of cell voltage inputs, wherein the respective input resistor is connected to the respective cell voltage input via a respective wire,

a respective capacitor that is connected to the respective wire and the midpoint potential voltage detection line,

a first respective balance line connected to the positive terminal of the respective battery cell and a second terminal of a first respective balance switch from the plurality of balancing switches via a respective balance resistor, and

a second respective balance line connected to the first respective balance line, the positive electrode of the respective battery cell, the respective input resistor and a first terminal of a second respective balance switch from the plurality of balancing switches.

2. The battery system monitoring apparatus according to claim 1, comprising a plurality of the cell controller ICs to monitor a plurality of cell groups.

3. The battery system monitoring apparatus according to claim 1, wherein a resistance value for each respective balance resistor is determined based on a resistance of the first input resistor, an overcharge protection voltage value of the battery cell, and a voltage value when the battery cell has a state of change (SOC) of 100%.

4. The battery system monitoring apparatus according to claim 3, wherein a resistance value for each respective balance resistor is determined based on a resistance of the first input resistor and a duty cycle of on and off of the plurality of balancing switches.

5. An electric storage device including the battery system monitoring apparatus according to claim 1, and a battery system.

6. An electric drive apparatus comprising the electric storage device according to claim 5.