| 摘要 |
<p>The circuit arrangement for transmitting real power from a DC voltage side to AC voltage-side connections has a first power converter (4) with load connections (5), in series with each of which second power converters (7) with a lower intermediate-circuit capacitor voltage are connected. This makes it possible to achieve finer voltage graduation of a sum voltage at the AC voltage-side connections (10). According to the invention, the second power converters (7) do not have their own real power supplies. There is thus no need for the previously used rectifiers for supplying the second power converters (7). In the method according to the invention, voltages of intermediate-circuit capacitances of power converters (4, 7) and a common-mode voltage of the AC voltage-side connections of the circuit arrangement are regulated by means of joint regulation. The intermediate-circuit capacitor voltages are, in particular, kept essentially constant, although the second rectifiers (7) interchange real power with a load (11) and with the first power converter (4). To this end, a change in the intermediate-circuit capacitor voltages is calculated in advance using a model of the converter, and the common-mode voltage is selected such that a weighted sum of the squares of the errors between the intermediate-circuitcapacitor voltages and the respective nominal values is minimized.</p> |
