Method of Monitoring and/or Controlling or Automatically Controlling the Voltage of at Least One Group of Cells in a Compound of Cells of an Energy Storage Device

• US 20090034159A1
• Filed: 08/07/2008
• Published: 02/05/2009
• Est. Priority Date: 02/07/2006
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Scharner, Sebastian, FROESCHL, Joachim
• Granted Patent: US 7,852,042 B2
• Time in Patent Office: Days
• US Class Current: 361/502
• CPC Class Codes: H02J 13/00002 characterised by monitoring
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H04B 2203/5412 by modofying wave form of the power source
• CPC Class Codes: H04B 2203/547 via DC power distribution
• CPC Class Codes: H04B 3/548 the power on the line being DC arrangements for feeding power H04L12/10; extracting feeding power from signals H04L25/02
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 10/30 State monitoring, e.g. fault, temperature monitoring, insulator monitoring, corona discharge
• CPC Class Codes: Y04S 40/121 using the power network as support for the transmission

Abstract

Thus, according to the invention, for monitoring and/or controlling or automatically controlling the voltage of at least one group of cells in a cell compound of an energy storage device, particularly an energy storage device in an onboard power supply system of a motor vehicle, a data communication is carried out between a central logic and a cell group logic by way of the rail line connecting the latter, in which case voltage levels exist between an idle level situated at or above a maximal voltage level, up to which the cell group logic exchanges energy with the rail line for charging or discharging the cell group, and a data level situated above the idle level.

Claims

1. A method of monitoring and controlling a voltage of at least one group of cells in a cell compound of an energy storage device in an onboard power supply system of a motor vehicle, comprising the acts of:

connecting a cell group logic to the group of cells by a supply line by which the group of cells is charged or discharged;

monitoring with the cell group logic the voltage of the group of cells;

controlling with the cell group logic charging or discharging of the group of cells, where the cell group logic takes energy from a rail line to charge the group of cells or feeds energy to the rail line from the group of cells; and

conducting a data communication between the cell group logic and at least one of another cell group logic and a central logic on the rail line at voltage levels between an idle voltage level which is equal to or greater than a predetermined maximal voltage level below which the group of cells is charged or discharged.

2. The method according to claim 1, further comprising the act of:

switching the cell group logic to active when the rail line voltage is determined to be above an enable voltage level which below the predetermined maximal voltage level.

3. The method according to claim 2, further comprising the act of:

transmitting power at or above a first power level between the rail line and the supply line when the rail voltage is determined to be greater than one of the enable voltage level and a low voltage level greater that the enable voltage level, and lower than a high voltage level which is less than or equal to the predetermined maximal voltage level.

4. The method according to claim 3, further comprising the act of:

transmitting power at or above a second power level greater than the first power level between the rail line and the supply line when a cell group voltage is above the enable voltage level and below the low voltage level, or above the high voltage level and below the predetermined maximal voltage level.

5. The method according to claim 4, wherein

the group of cells is one of a plurality of cell groups, and

supply lines of each of the plurality of cell groups are connected with the rail line such that power is at least one of transmitted between the plurality of cell groups, and transmitted between the plurality of cell groups and the rail line.

6. The method according to claim 5, wherein

the data communication includes data blocks for at least one of an address, a command, data, a safety function and a response.

7. The method according to claim 6, wherein

at least one of the data and the response include at least one of an internal resistance, a capacitance, a temperature and the voltage of a group of cells.

8. The method according to claim 7, wherein

the data communication is conducted by at least one of binary coding, amplitude coding, pulse duration coding and an amplitude—

pulse duration coding.

9. A cell group logic for monitoring and controlling the voltage of at least one group of cells in a cell compound of an energy storage device in an onboard power supply system of a motor vehicle in which the group of cells is connected by the cell group logic by way of a supply line by which the group of cells is charged or discharged, the cell group logic comprising:

a voltage comparator unit, the voltage comparator unit configured to monitor a voltage on a rail line and to carry out a data communication by way of the rail line between the cell group logic and at least one of another cell group logic and a central logic on the rail line at voltage levels between an idle voltage level which is equal to or greater than a predetermined maximal voltage level below which the group of cells is charged or discharged.

10. The cell group logic according to claim 9, wherein

a voltage comparator unit switches the cell group logic to active when the rail line voltage is above an enable voltage level which is below the predetermined maximal voltage level.

11. The cell group logic according to claim 10, further comprising

a switch unit,

wherein

the switch unit is controlled by the voltage comparator unit to connect the supply line of the group of cells to permit a power transfer between the group of cells and the rail line, and

the voltage comparator unit determines whether the power transfer is of removal of energy from, or the feeding of energy to, the rail line by monitoring voltage levels on the rail line and a cell group voltage.

12. The cell group logic according to claim 11, wherein

the data communication is conducted by at least one of binary coding, amplitude coding, pulse duration coding and an amplitude—

pulse duration coding.

13. A central logic for monitoring and controlling a voltage of at least one group of cells in a cell compound having at least one cell group logic in an energy storage device in an onboard power supply system of a motor vehicle, the group of cells being connected with the cell group logic by a supply line by which the group of cells is charged or discharged, the cell group logic monitoring and controlling the voltage of the group of cells by charging or discharging of the group of cells by) taking energy from a rail line or feeding energy to the rail line, wherein

a data communication takes place between the cell group logic and the central logic by way of the rail line, and

a voltage converter unit carries out data communication by way of the rail line when the voltage converter unit determines the presence of voltage levels between an idle level equal to or greater than a predetermined maximal voltage level below which the group of cells is charged or discharged, and a data voltage level greater than the idle voltage are impressed upon the rail line by the central logic.

14. The central logic according to claim 13, further comprising:

a control unit which drives the voltage converter unit to impress a rail voltage which is greater than an enable voltage level (U_enable) below the predetermined maximal voltage level in order to switch the cell group logic to active.

15. The central logic according to claim 14, wherein

the control unit drives the voltage converter unit to impress a rail voltage which is greater than the enable voltage level such that the cell group logic connects the supply lines of different cell groups so as to transmit power between at least one of different cell groups and at least one cell group and the rail line.

16. The central logic unit according to claim 14, wherein

the control unit drives the voltage converter unit to carry out the data communication between the cell group logic and the central logic on the rail line.

17. The central logic unit according to claim 13, wherein

the data communication is conducted by at least one of binary coding, amplitude coding, pulse duration coding and an amplitude—

pulse duration coding.