
14-6 Power Electronics and Motor Drives
bar P, while the output of leg b is connected to the negative bar N, generating an output voltage v
ab
= V
dc
.
A
general expression for the output voltage is
ab a b dc a b
,
(14.1)
By replacing in (14.1) the dierent binary combinations of the gate signals, it is easy to obtain the dif-
ferent output voltage levels listed in Table 14.2 and illustrated in Figure 14.6.
Note that two of them, (1,1) and (0,0), generate both a zero voltage level. is feature is called voltage-
level redundancy and can be used for other control purposes since it does not aect the voltage level
generated ...