Thales

Auxilec

Gérard Monroy

Christophe Bruzy

Francis Blanchery

Jacques Geray

The invention relates to an autotransformer for transforming a three-phase power supply into a nine-phase power supply, notably for use in a rectifier. The autotransformer is a, step-up or step-down transformer. For a step-down application, the three-phase input terminals E, E, E. are connected to one of the three main windings in delta configuration, mounted on respective magnetic branches M, M, Mof a magnetic circuit. Te main winding Bof one branch has intermediate taps K, K', K&#x2033;from which auxiliary windings X, Y, Z, mounted on the other branches, start. These auxiliary windings produce, on three output terminals A, B, C, voltages one of which is in phase with the three-phase supply voltage at E, the other phase-shifted by +40&#xb0;, and the third by +80&#xb0;. The number of turns in the auxiliary windings and the position of the intermediate taps are calculated so as to obtain this result. The identical windings of the other branches produce the other output voltages on the terminals A, B, C, A, Bin order to produce a system with nine phases.

40&#xb0; phase-shifting autotransformer

A DC-DC converter is provided, for example of the voltage booster type, comprising a switch controlled for chopping the input signal, a transformer whose primary winding receives the chopped signal and a means for rectifying the signal delivered by the secondary winding of the transformer. The switch is in parallel across a series assembly formed by the primary of the transformer and a capacitor. The rectifier means comprises a bridge for rectifying a current flowing in both directions.

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Beaumont sur Oise, France

Gérard Monroy