Reactive-power compensating circuit for polyphase load - automatically adjusts output amplitudes and phases of static converters

摘要

The reactive-power compensating circuit, for polyphase loads e.g. an arc furnace, has each of the static converters (11-13) coupled to the phase lines (1-3) designed to be self-commutating and with its thyristors (A-D) connected as a single-phase bridge. A transformer (14-16) is connected between the a.c. outputs of each converter and the a.c. supply (4). The converters are coupled in d.c. series with one another. A constant d.c. source (20) is coupled to the terminals (17, 18) of the series circuit. A control circuit (31-33) assigned to each converter sets the amplitude and phase of the output of that converter.