Drive control system for a multiphase motor powered by a power converter

A power converter circuit for providing electric energy to a multiphase motor, comprising:

• a first plurality of controllable converter valves connected to a positive busbar of a multi-pulsed bridge circuit and a second plurality of controllable converter valves connected to a negative busbar of the bridge circuit;
• a plurality of electrically isolating devices connected to the converter valves in one-to-one correspondence;
• and
• a drive control system including
• a control unit having an output side connected to an input side of the converter valves via the electrically isolating devices;
• an armature short-circuit braking device connected to an input side of electrically isolating devices of one bridge side of the bridge circuit;
• and over voltage recognition device having a first input terminal which receives a signal corresponding to a limit value and a second input terminal which receives a signal corresponding to a determined actual input voltage of the power converter;
• and
• a trigger circuit having an output side which is connected to the armature short-circuit braking device, and an input side which is connected to an output side of the overvoltage recognition device and supplied with a signal for the armature short-circuit braking device.

A method for providing a combined motor braking operation and overvoltage protection of a converter of a type including a multi-pulsed bridge circuit with a plurality of controllable converter valves, comprising the steps of:

• transmitting a status signal to a trigger circuit, the status signal corresponding to a status of an impulse suppression device;
• comparing an actual voltage value in a voltage intermediate circuit of a converter with a predetermined limit value to generate an output signal for input into the trigger circuit;
• and
• logically interlinking the output signal and the status signal by the trigger circuit to activate an armature short-circuit braking device, when at least one of the output signal and status signal changes its output potential to thereby effect an armature short-circuit by shorting converter valves of one bridge side of the bridge circuit while disabling converter valves of another bridge side of the bridge circuit.