Increasing thyristor utilisation in rectifier - forming effective, permitted, valve-rated current in rectifier in dependence on actual DC voltage at input

摘要

The utilisation and yield of thyristors is increased in rectifiers with superimposed d.c. voltage for compensation of reactive power. The thyristors (T1-6) have a presettable, max. valve OFF current. On exceeding of an effective, permitted valve-rated current the thyristors are switched-off, or controlled into a currentless state. The effective, permitted valve rated current of the thyristors in the rectifier (1) is formed in dependence on an actual d.c. voltage (Ud) at the rectifier d.c. voltage input (4, 5). Pref. the effective, permitted valve-rated current of the thyristors is proportional to a specified ratio, related to the idle d.c. voltage and the actual d.c. voltage at the input. USE/ADVANTAGE - GTO thyristors in rectifiers, with reactive power compensation and facility to load thyristors in reactive current operation up to thermal limit.