L. Malesani et al., AC DC/AC PWM CONVERTER WITH REDUCED ENERGY-STORAGE IN THE DC LINK/, IEEE transactions on industry applications, 31(2), 1995, pp. 287-292
The paper introduces the family of quasi-direct converters, i.e., forc
ed-commutated ac/dc/ac converters including small energy storage devic
es in the de Link, In particular, the case of three-phase to three-pha
se quasi-direct converter is considered. Since energy storage minimiza
tion calls for instantaneous input/output power balance, a proper cont
rol strategy is needed. The paper describes a simple and effective con
trol technique which also provides high-power factor and small distort
ion of the supply currents. After a discussion of the general properti
es of quasi-direct converters, design criteria of both power and contr
ol sections are given, and experimental results of a 2-kVA prototype a
re reported.