Traditionally, ac-ac conversion using semiconductor switches is done in two different ways: 1-in
two stages (ac-dc and then dc-ac) as in dc link converters or 2-in one stage (ac-ac)
cycloconverters (Fig. 1). Cycloconverters are used in high power applications driving induction
and synchronous motors. They are usually phase-controlled and they traditionally use thyristors
due to their ease of phase commutation.