POWER SUPPLY DEVICE FOR A NONLINEAR, TIME- VARYING LOAD

摘要

The invention relates to an electrical power supply device for a nonlinear, temporally varying load (1), comprising an electrical power system (2) having a plurality of phases (3). The nonlinear, temporally varying load (1) and a var compensator (5) are connected to the phases (3) of the electrical power system (2). The var compensator (5) is designed as a multilevel converter having a plurality of strands (6). The strands (6) of the multilevel converter (5) are each connected to one of the phases (3) of the electrical power system (2) at one end and are connected to each other at a common star point (7) at the other end. The common star point (7) of the multilevel converter (5) is connected to a star point (12,15) of an additional device (8,14) connected to the phases (3) of the electrical power system (2) so that the common star point (7) of the multilevel converter (5) is connected to the phases (3) of the electrical power system (2) both by means of the strands (6) of the multilevel converter (5) and by means of the additional device (8,14). The connection by means of the additional device (8,14) is designed in such a way that there is a low- resistance connection of the common star point (7) of the multilevel converter (5) to the phases (3) of the electrical power system (2) with respect to the electrical power zero sequence system of the electrical power system (2) and a high resistance connection of the common star point (7) of the multilevel converter (5) to the phases (3) of the electrical power system (2) with respect to the electrical power positive sequence system of the electrical power system (2) and the electrical power negative sequence system of the electrical power system (2).