APPARAT FOER TRANSFORMERING OCH OMRIKTNING AV VAEXELSTROEM TILL LIKSTROEM FOER ELKRAFTTRANSMISSIONSSYSTEM

摘要

The transformer DC winding id divided into a number of part windings which are connected to series-coupled six pulse bridges, in which the individual valve functions are simplified, comprising a very small number of high effect thyristors in each valve. The three-phase convertor has its part windings on the DC side arranged using Y, delta and Z couplings, with the composition of the Y and delta windings being such that a pulse train higher than the customary 12-pulse system can be formed in the converter. - The valve function may comprise only one high effect thyristor, and ignition by light signal is provided to the thyristor without electrical intermediary connection. Cooling of the transformer and valve parts can be by a common medium which is also the insulator for the transformer part. The medium can be liq. or gas-form.