Abstract: A converter circuit arrangement is disclosed for matching a variable DC voltage to a drive circuit for producing drive signals and having a three-point DC voltage intermediate circuit (2), which three-point DC voltage intermediate circuit (2) is formed by a first capacitor (3) and a second capacitor (4) connected in series with it, with one connection of the first capacitor (3) forming an upper connection (5) of the three-point DC voltage intermediate circuit (2), and the first capacitor (3) forming a center point connection (6) at the junction point with the second capacitor (4) and one connection of the second capacitor (4) forming a lower connection (7) of the three-point DC voltage intermediate circuit (2).

Abstract: A short circuit within the dynamic voltage restorer (1) is immediately detected by a short circuit detection units (9) which permanently monitors currents and voltages in the voltage source converter (3) and energy storage capacitor bank (2). Upon detection a fast discharge of the capacitor bank (2) including firing of all available semiconductors of the voltage source converter (3) and distributing the resulting current stress as evenly as possible within the voltage source converter (3) is initiated. Instead of letting costly fuses interrupt the high short circuit currents, these currents are detected and evenly distributed within the converter.

Abstract: The invention specifies a disconnector for decoupling a load from a supplying AC power supply system. The disconnector comprises a transformer whose primary is connected into the AC power supply system. On the secondary side, a rectifier circuit is provided which has a turn-off thyristor connected to it. In normal operation, the turn-off thyristor is kept closed, so that the power supply system supplies the load. In the event of power supply system faults or interruptions, the turn-off thyristor is opened, which disconnects the power supply system from the load owing to the transformer impedance.