Patent ID: 6670815
Filing Date: 2003-12-30
Classification: G01R,G05B,H02H

Abstract:
Process for operating an electric motor drive, comprising feeding an electric consumer (6) from an a.c. network, rectifying an input alternating voltage and applying an intermediate circuit voltage so obtained to half bridges of a bridge circuit, whereby each of the half bridges has two bridge arms (7a, 7b) in which at least one semiconductor switch (8a, 8b) is arranged, to which control signals are applied through an actuation circuit (9a, 9b) fed from an auxiliary supply voltage, wherein in each of the bridge arms (7a, 7b) connected at any given time to one of the poles (4) of an intermediate circuit voltage, conducting a test shut off of the auxiliary supply voltage applied to one of the actuation circuits (9a, 9b) of the semiconductor circuit (8a, 8b), monitoring the test shut off by a measurement, and when an error occurs, shutting off at least the auxiliary supply voltages applied to the actuation circuits (9a, 9b) of the bridge arms (7a, 7b) of the half bridges connected to the other pole of the intermediate circuit voltage.