Electrical power converter with pre-charge mode of operation

An electrical converter for converting an AC signal having three phase voltages into a DC signal, the electrical converter comprising:

• three phase terminals (A, B, C), a first DC terminal (P), and a second DC terminal (N);
• a first converter stage comprising a three-phase bridge rectifier connecting the three phase terminals to an upper intermediate node (x) and a lower intermediate node (y), and a phase selector comprising first active switches (Saza, Sbzb, Sczc) connecting the three phase terminals to a middle intermediate node (z);
• an output filter comprising at least one capacitor (CPm, CmN) connected across the first and second DC terminals (P, N);
• a second converter stage arranged between the first converter stage and the output filter, wherein the second converter stage comprises a switch node (t) and a pair of second switches (SPz, SzN) connecting the switch node (t) to a respective one of the first and second DC terminals (P, N), wherein the middle intermediate node (z) is connected to the switch node (t);
• and
• a controller implemented with a first mode of operation configured to convert the AC signal into the DC signal;
• wherein the controller is implemented with a second mode of operation, in which the electrical converter is configured to disconnect the upper intermediate node (x) and/or the lower intermediate node (y) from all the phase terminals (A, B, C), and in which the controller is configured to control switching of the first switches (Saza, Sbzb, Sczc) while keeping the upper intermediate node (x) or the lower intermediate node (y) disconnected from all the phase terminals (A, B, C), such that a current is allowed to flow between the middle intermediate node (z) and the output filter (15), allowing for stepwise increasing a voltage across the output terminals (P, N) during start-up.