| CPC H02M 1/4216 (2013.01) [H02M 1/4225 (2013.01); H02M 7/217 (2013.01); H02M 1/0085 (2021.05); H02M 1/10 (2013.01); H02M 1/325 (2021.05)] | 18 Claims |
|
1. A circuit arrangement comprising a 3-phase PFC stage with three connection terminals to connect a first phase L1, a second phase L2, and a third phase L3 that provides an output power in 3-phase operation, the circuit arrangement being configured to also operate in single-phase operation by a switching arrangement composed of a first independently controllable switch S1 bridged by a first diode D1 and a second independently controllable switch S2 bridged by a second diode D2 connected between a DC link of a 3-phase rectifier circuit and a rectifier-diode bridge with rectifier diodes,
wherein the first phase L1, the second phase L2, and the third phase L3 are brought together via respective a first line path LP1, a second line path LP2, and a third line path LP3 at a neutral point,
wherein a first bidirectional switch S3, a second bidirectional switch S4, and a third bidirectional switch S5 is provided in each of the first line path LP1, the second line path LP2, and the third line path LP3 for the purpose of activating and deactivating the respective first phase L1, the second phase L2, and the third phase L3 at the neutral point,
wherein the first bidirectional switch S3, the second bidirectional switch S4, and the third bidirectional switch S5 are opened or closed in the phases in a controlled manner for single-phase PFC operation in order to adjust a current over two active phases sinusoidally and in phase with a grid; the single-phase PFC operation providing the same output power as the 3-phase operation;
wherein the DC link, in addition to a main DC link capacitor C1, also has a capacitor C2 that can be additionally connected via a switch S;
wherein, prior to the first bidirectional switch S3, the second bidirectional switch S4, and/or the third bidirectional switch S5, being opened or closed for single-phase PFC operation, the current at the connection of the second phase L2 is first adjusted to a predefined value, which can also be zero.
|