Page 251 - Power Electronics Handbook

Cycloconverter control circuits 241

1

+ r -

Reference Positive
voltage , Delay - Distribute - thyristor Load
and
frequency. group
V0%-
t
OV
Negative
thyristor

1
Load current feedback
IFbprc 10.21 Block schematic of a cycloconvertcr control circuit

The control circuits for cycloconverters can become very complex owing
to the relatively involved logic functions which have to be performed and
the large number of thyristors requiring gate signals. To construct such a
drive using discrete components would result in a large and expensive
system, so modem cycloconverter circuits use a considerable amount of
integrated circuits, many of them implemented as gate arrays, with complex
logic performed in the software of microprocessors.