AC charging of an intelligent battery
A method for AC-charging an intelligent battery pack, which is connected to a charging column and has at least two battery modules, which each comprise at least one energy storage element and at least two power semiconductor switches, which interconnect the respective battery module in series or in parallel with another battery module. The battery pack is connected for charging with alternating current provided by the charging column by a charging circuit, which includes a filter and a rectifier. According to the method, a state of each individual energy storage element is monitored. In accordance with a continued evaluation of the states of the respective energy storage elements, a terminal voltage of the battery pack is adjusted by way of dynamic actuation of the power semiconductor switches to a voltage provided by the rectifier.
1. A method for AC-charging an intelligent battery pack, which is connected to a charging column and has at least two battery modules, which each comprise at least one energy storage element and at least two power semiconductor switches, which interconnect the respective battery module either in series or in parallel with another battery module, in which the battery pack is connected for charging with alternating current provided by the charging column by way of a charging circuit, which comprises a filter and a rectifier, the method comprising:
measuring a charging voltage and a charging current;
monitoring a state of each individual energy storage element;
continuously evaluating the states of the respective energy storage elements based on the measured charging voltage and the measured charging current; and
adjusting a terminal voltage of the battery pack by dynamically actuating the power semiconductor switches to a voltage provided by the rectifier in accordance with the continuous evaluation of the states of the respective energy storage elements.
2. The method as claimed in claim 1 , further comprising suppressing an inrush current brought about by a voltage difference between the battery pack and the charging column using the filter.
3. The method as claimed in claim 1 , further comprising controlling a charging power by way of the dynamic actuation of the power semiconductor switches.
4. The method as claimed in claim 1 , further comprising preventing surge currents using a phase-locked loop connected to the charging column.
5. The method as claimed in claim 1 , further comprising performing a power factor correction without an electric circuit for power factor correction.
6. The method as claimed in claim 1 , further comprising reproducing an output voltage profile prescribed by the rectifier by a dynamic interconnection of the battery pack in order to create optimum charging conditions at any given moment.
7. The method as claimed in claim 6 , further comprising averaging out over time of temporally short voltage differences which arise between the output voltage profile prescribed by the rectifier and the terminal voltage of the battery pack.