| Abstract |
Several types of AC/AC converters may be used in order to regulate the power provided to an unbalanced resistant 3-phase receiver. The different structures are compared, in terms of the harmonics injected into the supply as well as of the unbalance of the absorbed currents. By use of a symmetrical control, the all-thyristor AC/AC converter is the model which offers the lowest overall harmonic level, as well as being the only one where the unbalance is reduced when the regulating is increased. Such properties may be used for purposes of supply from a 3-phases network with a mid-point resistances. The only value in using dissymmetrical control is for three single-phase AC/AC converters in delta configuration. It allows for the cancellation of the inverted component of the absorbed current fundamental. The use of a highly simplified dissymmetrical control enables the unbalance to be considerably reduced. |
