Strömriktare samt förfarande för styrning därav

摘要

A converter has a resonance circuit with an auxiliary valve (18), an inductor (17) and capacitive members (15) for assisting the commutation of the converter. A control arrangement (24) is adapted to control turning-on and turning-off of controllable semiconductor devices of the main valve of the converter and controllable semiconductor components of the auxiliary valve. Means are arranged for measuring the current in the phase output (10) of the converter. When carrying out two subsequent commutation processes for changing the phase potential on the phase output from the potential of a first of the poles of a direct voltage side of the converter to that of a second of the poles and then back to the one of the first pole the second commutation process is started before the first one has been completed.