2) 2nd stage (t1, t2) – Fig. 9(b)
At instant t1, S2 is turned off the energy stored in L2 is
transferred to the load through diodes D2, D4 e D6. Currents
iD4(t) and iD6(t) are adds to currents iS1(t) and iS3(t),
respectively. This stage finishes at instant t2 when S2 is turned
on.
3) 3rd stage (t2, t3) – Fig. 9(a)
At instant t2, S2 is turned on and the first stage is repeated.
With the energy of the source being stored at inductances L1,
L2 and L3. This stage finishes at instant t3 when S3 is turned
off.