Abstract: A drive controller for a self-commutated converter is described. The converter has two half-bridges, and the drive controller includes a corresponding control circuit for the converter valves of each half-bridge. Each control circuit can be connected via first switches to an external voltage. Each first switch is connected in parallel with a second switch, wherein the second switches are decoupled by way of decoupling diodes. The first and second switches can be alternatingly switched on and off. The switches can therefore be cyclically tested without interrupting service.

Abstract: A drive controller for a self-commutated converter having two half-bridges with converter valves, includes two control circuits, with each control circuit associated with a corresponding half-bridge and operatively connected with the converter valves of that half-bridge, and at least two switches, wherein an input of each switch is directly or indirectly connected to an external voltage, and an output of each switch is directly or indirectly connected to a pulse-inhibiting path. Further provided are at least two pulse-inhibiting controllers, wherein each switch receives control signals from a corresponding one of the pulse-inhibiting controllers. Arranged in the pulse-inhibiting path is a buffer unit for briefly maintaining a supply voltage of the control circuits if a pulse-inhibiting path electrically disconnects at least one of the control circuits from the external voltage.