| Abstract |
Thyristor regulators are normally used to regulate the power supplied to an alternative load. Their use may pose certain problems to the power network and the use of turn-off switches may be envisaged. An easily applied P.W.M. strategy enables the current wave to be realigned and the first harmonics to be directed towards higher frequencies, thus making any filtering much easier. In three-phase mode, only three arrangements are possible. This paper aims to compare these and, in particular, to show that the delta-connected regulator arrangement, combined with a suitable chopping frequency, brings about a considerable reduction in line current harmonics and a consequent improvement in the converter power factor. |
