Arrangement of a battery system using DC/DC converters for a vehicle
A battery system includes a plurality of groups of series-connected battery cells, a plurality of DC/DC converters and a first switch. The groups of series-connected battery cells are themselves in turn connected in series. The DC/DC converters are connected on the input side to a first pole and to a second pole of a group of battery cells associated with the respective DC/DC converter, and are connected in series on the output side between a first output of the battery system and a second output of the battery system. The first switch is connected in a first current path between the first pole of a first group of battery cells and the first output of the battery system, and has a control input, which is connected to a controller, for a first control signal.
1. A battery system comprising:
a first output and a second output;
a plurality of groups of series-connected battery cells, the groups being connected in series and each of the groups having a first pole and a second pole;
a plurality of DC/DC converters, each of the DC/DC converters including an input side and an output side, the input side of each of the DC/DC converters being connected between the first pole and the second pole of one of the groups of battery cells, and the output side of each of the DC/DC converters being connected in series between the first output and the second output; and
a first switch connected in a first current path between the first pole of a first group of battery cells and the first output that bypasses the DC/DC converters, the first group of battery cells being located at one end of the plurality of groups, and the first switch being configured to connect the first pole of the first group to the first output in response to a first control signal from a controller,
wherein the DC/DC converters are configured to output a first output power,
wherein the battery cells are configured to output a second output power, the second output power being greater than the first output power, and
wherein the controller is configured to output the first control signal to the first switch such that the second output power is supplied to the first output when a demanded total output power of the battery system is higher than the first output power.
2. The battery system as claimed in claim 1 , wherein:
the input sides of the DC/DC converters are configured to be galvanically isolated from the first output and the second output.
3. The battery system as claimed in claim 2 , wherein:
the DC/DC converters are fly-back, half-bridge, full-bridge or transformer-based resonant converters.
4. The battery system as claimed in claim 1 , wherein:
the plurality of DC/DC converters are configured to be unidirectional.
5. The battery system as claimed in claim 1 , further comprising:
a first diode connected in a second current path, the second current path being parallel with the first current path and the first diode being connected in a first forward-biased direction configured to provide a charging current to the battery cells.
6. The battery system as claimed in claim 5 , wherein:
the first current path has a second diode connected in series with the first switch, and
the second current path has a second switch connected in series with the first diode, the second diode being connected in a second forward-biased direction configured to receive a discharge current from the battery cells.
7. The battery system as claimed in claim 1 , wherein:
a total output voltage of the DC/DC converters is configured to be set higher than a battery voltage of the series-connected battery cells, and
the controller is configured to separately preset an output power of each of the DC/DC converters.
8. A motor vehicle, comprising:
an electric drive motor configured to drive the motor vehicle; and
a battery system including:
a first output and a second output;
a plurality of groups of series-connected battery cells, the groups being connected in series and each of the groups having a first pole and a second pole;
a plurality of DC/DC converters, each of the DC/DC converters including an input side and an output side, the input side of each of the DC/DC converters being connected between the first pole and the second pole of the one of the groups of battery cells, and the output side of each of the DC/DC converters being connected in series between the first output and the second output; and
a first switch connected in a first current path between the first pole of a first group of battery cells and the first output that bypasses the DC/DC converters, the first group of battery cells being located at one end of the plurality of groups, and the first switch is configured to connect the first pole of the first group to the first output in response to a first control signal from a controller,
wherein the DC/DC converters are configured to output a first output power,
wherein the battery cells are configured to output a second output power, the second output power being greater than the first output power, and
wherein the controller is configured to output the first control signal to the first switch such that the second output power is supplied to the first output when a demanded total output power of the battery system is higher than the first output power.