Once the switch Sn is turned off, the energy in the inductor is transferred
to the top capacitor through the antiparallel diodeDp. Similarly,
for a negative dc component, Vdc1 will become greater than
Vdc2, requiring the operation of switch Sp and diode Dn. Various
control strategies like single pulse control, multipulse control,
and proportional–integral (PI) duty cycle control schemes
are suggested to control the chopper [15].