Patent ID: 7529111
Filing Date: 2009-05-05
Classification: H02M

Abstract:
1. A drive controller for a self-commutated converter having two half-bridges with converter valves, said drive controller comprising: a first control circuit having input terminals connected to phase outputs of the converter valves in one-to-one correspondence and receiving from the converter valves corresponding load phase currents, and separate outputs operatively connected to corresponding couplers that each control a converter valve of one of the half-bridges; a second control circuit operatively connected to the first control circuit and having separate outputs operatively connected to corresponding couplers that each control a converter valve of the other half-bridge; wherein each of the couplers is connected via a dedicated pulse inhibiting path to a dedicated controllable switch configured for separately disconnecting the respective dedicated pulse inhibiting path from an external voltage, with a corresponding control input of each dedicated controllable switch receiving a respective control signal from one of the first and second control circuits for disconnecting the respective dedicated controllable switch from the external voltage if a load phase current received from a corresponding converter valve has negative polarity.