CONTROL OF A SECONDARY BATTERY WITH BATTERY CELLS WHICH CAN BE CONNECTED IN SERIES WITH ONE ANOTHER

Abstract

The invention relates to an open-loop and/or closed loop control system (1) for a secondary battery (3), having at least two battery cells (2) which can be electrically connected in series with one another, in particular of a motor vehicle which can be powered electrically, having—at least two cell electronics units (4) which are each assigned to at least one battery cell (2),—at least one electronic central processor unit (5) and—at least one communication link (6) via which the electronic central processor unit (5) can be connected in terms of communication technology to the cell electronics units (4),—wherein the electronic central processor unit (5) is configured to detect an electrical actual output voltage which is respectively generated by the secondary battery (3) and to compare said actual output voltage with a predefined electrical setpoint output voltage, to generate at least one control signal as a function of the respective result of the comparison between the electrical actual output voltage and the electrical setpoint output voltage and to transmit the respectively generated control signal to all the cell electronics units (4) via the communication link (6),—wherein each cell electronics unit (4) is configured to detect a respective state of the battery cell (2) assigned thereto, to generate a state parameter assigned to the respectively detected state, to weight, with the respective state parameter, a value, stored in the cell electronics unit (4), of a probability of the battery cell (2), assigned thereto, being switched on and to control the state of the battery cell (2), assigned thereto, as a function of the respective control signal and the value, weighted with the respective state parameter, of the probability of the battery cell (2) being switched on, and—wherein the respective control signal contains at least one information item according to which the values, stored in the cell electronics units (4), of the probability of the respective battery cell (2) being switched on are to be retained, incrementally increased, incrementally reduced or reset to a predefined output value in the next control step.

Claims

1. An open-loop and/or closed-loop control system (1) for a secondary battery (3) comprising at least two battery cells (2) connected together electrically in series, comprising at least two cell electronic units (4) each assigned to at least one battery cell (2), at least one central electronic unit (5), and at least one communications connection (6), providing a communications link between the central electronic unit (5) and the cell electronic units (4), wherein the central electronic unit (5) is configured to detect and to compare, with a definable setpoint output voltage an actual output voltage currently produced by the secondary battery (3), to generate at least one control signal based on the current result of the comparison between actual output voltage and setpoint output voltage, and to send the currently generated control signal to all the cell electronic units (4) via the communications connection (6), wherein each cell electronic unit (4) is configured to detect a currently existing state of its assigned battery cell (2), to generate a state parameter associated with the currently detected state, to weight by the currently existing state parameter a value stored in the cell electronic unit (4) for a probability of enabling its assigned battery cell (2), and to control the state of its assigned battery cell (2) according to the currently existing control signal and the value for the probability of enabling the battery cell (2), which value is weighted by the currently existing state parameter, and wherein the currently existing control signal contains at least one piece of information which specifies whether, in the next control step, the values stored in the cell electronic units (4) for the probability of enabling the associated battery cell (2) are to be retained, incremented, decremented or reset to a definable initial value.

2. The open-loop and/or closed-loop control system (1) as claimed in claim 1, characterized in that the currently existing control signal contains information which specifies whether battery cells (2) must are to be enabled or disabled in a positive orientation and/or which specifies whether battery cells (2) must are to be enabled or disabled in a negative orientation.

3. A method for open-loop and/or closed-loop control of a secondary battery, which battery system comprises a secondary battery (3) comprising at least two battery cells (2) connected together electrically in series, at least two cell electronic units (4) each assigned to at least one battery cell (2), at least one central electronic unit (5) and at least one communications connection (6), which can be used to provide a communications link between the central electronic unit (5) and the cell electronic units (4), wherein the central electronic unit (5) detects and compares, with a definable setpoint output voltage an actual output voltage currently produced by the secondary battery (3), to generate at least one control signal based on the current result of the comparison between actual output voltage and setpoint output voltage, and to send the currently generated control signal to all the cell electronic units (4) via the communications connection (6), wherein each cell electronic unit (4) is used to detect detects an instantaneous state of its assigned battery cell (2), generates a state parameter associated with the currently detected state, weights, by the currently existing state parameter, a value stored in the cell electronic unit (4) for a probability of enabling its assigned battery cell (2), and controls the state of its assigned battery cell (2) based on the currently existing control signal and the current value for the probability of enabling the battery cell (2), which value is weighted by the state parameter, and wherein at least one piece of information, which specifies whether, in the next control step, the values stored in the cell electronic units (4) for the probability of enabling the relevant battery cell (2) are to be retained, incremented, decremented or reset to a definable initial value, is used as the currently existing control signal.

4. The method as claimed in claim 3, characterized in that the currently existing control signal contains information which specifies whether battery cells (2) are to be enabled or disabled in a positive orientation and/or which specifies whether battery cells (2) are to be enabled or disabled in a negative orientation.

5. The method as claimed in claim 1, wherein the secondary battery (3) is a battery of an electrically powered vehicle.

6. The method as claimed in claim 3, wherein the secondary battery is a battery of an electrically powered vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The invention is explained by way of example below using a preferred exemplary embodiment with reference to the enclosed drawing, where the features presented below may constitute, both each individually and in various combinations with one another, an aspect of the invention, in which drawing:

[0035] FIG. 1 is a schematic diagram of an exemplary embodiment of an open-loop and/or closed-loop control system according to the invention.

DETAILED DESCRIPTION

[0036] FIG. 1 shows a schematic diagram of an exemplary embodiment of an open-loop and/or closed-loop control system 1 according to the invention for a secondary battery 3 of an electrically powered vehicle, which secondary battery comprises a plurality of battery cells 2 which can be connected together electrically in series. The open-loop and/or closed-loop control system 1 comprises a plurality of cell electronic units 4 each assigned to a battery cell 2, a central electronic unit 5 and a communications connection 6, which can be used to provide a communications link between the central electronic unit 5 and the cell electronic units 4.

[0037] The central electronic unit 5 is designed to detect and to compare with a definable setpoint output voltage an actual output voltage currently produced by the secondary battery 3, to generate at least one control signal according to the current result of the comparison between actual output voltage and setpoint output voltage, and to send the currently generated control signal to all the cell electronic units 4 via the communications connection 6.

[0038] Each cell electronic unit 4 is designed to detect a currently existing state of its assigned battery cell 2, to generate a state parameter associated with the currently detected state, to weight by the currently existing state parameter a value stored in the cell electronic unit 4 for a probability of enabling its assigned battery cell 2, and to control the state of its assigned battery cell 2 according to the currently existing control signal and the value for the probability of enabling the battery cell 2, which value is weighted by the currently existing state parameter.

[0039] The currently existing control signal contains at least one piece of information, which specifies whether, in the next control step, the values stored in the cell electronic units 4 for the probability of enabling the relevant battery cell 2 must be retained, incremented, decremented or reset to a definable initial value. In addition, the currently existing control signal can contain information which specifies whether battery cells 2 must be enabled or disabled in a positive orientation and/or which specifies whether battery cells 2 must be enabled or disabled in a negative orientation.