About current distribution in paralleled thyristors of very high current controlled rectifiers: analysis of a real case

It is very well known that in high current transformer-rectifiers several thyristors in parallel must be used in each secondary phase. Current distribution between paralleled thyristors also depends on rectifier structure and this thyristors current not always are given by total secondary phase current divided by the number of thyristors, as in ideal cases. In this paper a real case of current distribution is analyzed for a 35 kA, 6 pulses controlled rectifier. Conclusions and recommendations concerning the selection of thyristors for this type of rectifiers are given.