A high performance single stage Power Factor Correction (PFC) converter with
tight
output voltage regulation and a very simple circuit to carry out those functions,
which means its cost is lower than its counterparts. Two basic flyback circuits
include a simple control circuit. For the hard switching circuit, only one switch
is used to achieve low cost; for the soft switching scheme, one auxiliary switch
is added to get higher efficiency and smaller size. There are two power flow paths,
resulting in part power processed by an active switch only once to reduce the current
stress and improve the efficiency. A direct current (DC) bus voltage will be limited
to the peak value of input voltage. The maximum DC bus voltage will be less than
400 and a single commercial capacitor can be used for universal voltage stress
under light load condition.