System zum Begrenzung des Stromes eines Spannungsumrichters

摘要

A current transformer (4) detects the output currents of a voltage-type inverter (INV), and comparators (11) check whether the outputs from the current transformer exceed a predetermined limit value. When the comparators (11) detect that the magnitude of the current vector exceeds the predetermined limit value and the motor is driven, selected phases of the inverter are switched off whereas in the case of motor braking all phases are switched off. This ensures that the output current of the inverter (INV) will be reduced.