“…The three-level Power Factor Correction (PFC) VIENNA topology was invented by W. Kolar [34]. As shown in Figure 1, the single-phase five-level VIENNA converter works like a three-level BOOST on each half of the cycle: if the input current is positive, the cells {T 1 , D 1 }, {T 2 , D 5 } form a three-level BOOST with the flying capacitor C f1 and the midpoint return diode D 4 ; if the current is negative, the cells {T 2 , D 2 }, {T 1 , D 6 } form a three-level BOOST with the flying capacitor C f2 and the midpoint return diode D 3 [35]. It allows the input inductance to be divided by 4 and, above all, it allows us to take advantage of serial redundancy, i.e., fault tolerance.…”