Method for electrically charging an energy store by switching between two configurations

Abstract

A method for electrically charging an energy store. The method includes the following steps: starting an electrical charging process for the energy store in a first configuration; interrupting the charging process, changing the configuration of the energy store from the first configuration to a second configuration, and resuming the charging process in the second configuration. The energy store in the first configuration is designed to be charged with a higher electrical voltage than in the second configuration.

Claims

1. A method for electrically charging an energy storage element, wherein the method comprises the steps of: starting an electrical charging process for the energy storage element, which is maintained in a first configuration (S1), by charging the energy storage element with electrical energy from an energy source; activating an electrical consumer (S3) prior to interrupting the charging process (S4) to the energy storage element; interrupting the charging process (S4) to the energy storage element; supplying the electrical consumer with electrical energy using the energy source during the interrupting step; changing the configuration of the energy storage element from the first configuration to a second configuration (S5), wherein the energy storage element in the first configuration is configured to be charged with a higher electrical voltage than in the second configuration; and resuming the charging process to the energy storage element in the second configuration (S6).

2. The method as claimed in claim 1, wherein the energy storage element in the second configuration has two energy storage element modules electrically connected in parallel with one another.

3. The method as claimed in claim 1, wherein the electrical consumer is switched off (S7) after resuming the charging process.

4. The method as claimed in claim 1, wherein interrupting the charging process is carried out if a voltage present between two electrical poles of the energy storage element reaches or exceeds a first voltage threshold value.

5. The method as claimed in claim 4, wherein the charging process is carried out with electric current, wherein a current intensity of the current (S2) is reduced if the voltage present between two electrical poles of the energy storage element is greater than a second voltage threshold value.

6. The method as claimed in claim 5, wherein the current intensity is increased (S8) after resuming the charging process.

7. The method as claimed in claim 5, wherein the current intensity is reduced to a value that is adapted to an electrical consumer.

8. A device for electrically charging an energy storage element, said device comprising: a control unit configured to (i) start an electrical charging process for the energy storage element, which is maintained in a first configuration (S1), by charging the energy storage element with electrical energy from an energy source (ii) activate an electrical consumer (S3) prior to interrupting the charging process (S4) to the energy storage element; (iii) interrupt the charging process (S4) to the energy storage element, (iv) supply the electrical consumer with electrical energy using the energy source during the interrupt, (v) change the configuration of the energy storage element from the first configuration to a second configuration (S5), wherein the energy storage element in the first configuration is configured to be charged with a higher electrical voltage than in the second configuration, and (vi) resume the charging process to the energy storage element in the second configuration (S6).

9. A motor vehicle, comprising the device as claimed in claim 8.

10. The device of claim 8, wherein the control unit is further configured to (vii) deactivate the electrical consumer (S7) after resuming the charging process.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features and advantages of the present invention will become clear on the basis of the following description of preferred exemplary embodiments with reference to the accompanying drawings.

(2) FIG. 1 shows a schematic flow diagram of a method according to one embodiment of the invention; and

(3) FIG. 2 shows a schematic block diagram of a device according to one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(4) The first step of the method S1 involves starting a charging process for an energy store in a first configuration. Step S2 involves detecting that the voltage at the electrical poles of the energy store is approaching the voltage value maximally attainable by the device used for the charging process. The current intensity emitted by the device is thereupon reduced.

(5) Step S3 involves switching on an electrical consumer that draws the electric current emitted by the device. Step S4 then involves interrupting the charging process, for example by galvanically isolating the energy store from the device. This can be carried out for example by one or more contactors. In this state, the device supplies only the electrical consumer.

(6) Consequently, for the device there is no difference in comparison with charging the energy store. Consequently, the method can be used even for devices which do not actually allow the charging process to be interrupted. An interaction of a user is likewise not necessary.

(7) Step S5 involves changing the configuration of the energy store from the first configuration to a second configuration. In the second configuration, two energy store modules are connected in parallel to one another, said modules being connected in series in the first configuration. This has the consequence that the voltage required for completely charging the energy store is halved. It can thus be achieved even by a device which could not attain the voltage required for complete charging in the first configuration.

(8) Step S6 then involves resuming the charging process. Afterward, step S7 involves switching off the electrical consumer since the latter is no longer required. In step S8, the current intensity can then be increased again in order to achieve rapid charging.

(9) As a result of the charging of the energy store in the first configuration in step S1, more rapid charging is achieved than if the charging were carried out exclusively in the second configuration.

(10) The device 100 in FIG. 2 comprises a control unit 101. The device 100 is designed to carry out the method described with reference to FIG. 1. The control unit 101 is designed to detect a voltage maximally attainable during the charging process by the device 100 and to carry out the method if the maximally attainable voltage is less than the voltage required for completely charging the energy store in the first configuration.