Page 318 - Power Electronics Handbook

308 D.C. link frequency changers

Flgurc 13.28 Recovery of commutation energy in the inverter of Figure 13.20

13.2.4.3 Voltage boosting
Increasing the available commutation in proportion to the load current
improves the efficiency of the circuit, and this occurs in several inverter
circuits as part of the circuit function. In these instances it may sometimes
be necessary to limit the amount of voltage boost by use of feedback
windings to the supply, as discussed in the previous section. In applications
where voltage boosting does not occur naturally, auxiliary circuits can be
used.
In the coupled-pulse commutated circuit of Figure 13.20 the maximum