Patent ID: 6049474
Filing Date: 2000-04-11
Classification: H02M

Abstract:
Method of control of a three-phase or multi-three-phase invertor (1) comprising switching means (8,9,10,11,12,13) linking the outputs of the invertor to a DC voltage source (2), the invertor being controlled by means (5) for deriving, in the course of successive slaving cycles, signals for pulse-width-modulation control of the switching means on the basis of the phase currents obtained according to the preceding measurements of the power supply line current of the invertor, wherein within a pulse-width-modulation period, a time interval (u1, u2) between the instant of switching of a switching means of one phase and the instant of switching of a corresponding switching means of a following phase becomes less than a predetermined threshold value, preventing the measurement, it consists in generating a pulse-width modulation defining a measurement time interval (measurement u1; measurement u2) of sufficient duration to allow measurement of the effects of the said switching on the line current and in reducing the duration of the other pulse-width modulations, contained in the same slaving cycle, by a value such that the sum of the reductions of these other pulse-width modulations compensates for the increase in the pulse-width modulation defining the said measurement interval.