State

Output voltage ( $V_{ab}$ )

Direction of output current ( $I_{out}$ )

Switches in ON states

1)

$3V_{dc}$

Positive

$S_3,Q_1,Q_2$

2)

$2V_{dc}$

Positive

$S_2,Q_1,Q_2$

3)

$V_{dc}$

Positive

$D_{S1},Q_1,Q_2$

4)

$V_{dc}$

Negative

$S_1,D_{Q1},D_{Q2}$

5)

0

Positive

$Q_1,D_{Q3}$ or $Q_2,D_{Q4}$

6)

0

Negative

$Q_3,D_{Q1}$ or $Q_4,D_{Q2}$

7)

$-V_{dc}$

Positive

$S_1,D_{Q3},D_{Q4}$

8)

$-V_{dc}$

Negative

$D_{S1},Q_3,Q_4$

9)

$-2V_{dc}$

Negative

$S_2,Q_3,Q_4$

10)

$-3V_{dc}$

Negative

$S_3,Q_3,Q_4$