| CPC H02M 1/0077 (2021.05) [H02M 1/0074 (2021.05); H02M 3/33584 (2013.01); H02M 7/758 (2013.01)] | 9 Claims |
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1. An AC/DC converter comprising:
a three-phase transformer or three single-phase transformers defining a first primary winding, a second primary winding and a third primary winding;
a plurality of first secondary windings magnetically linked with the first primary winding, a plurality of second secondary windings magnetically linked with the second primary winding and a plurality of third secondary windings magnetically linked with the third primary winding;
a plurality of first, second and third reconfigurable connection modules each of which is respectively connected on the input side with a first, a second and a third secondary winding;
the outputs of the first reconfigurable connection modules being connected in series to one another, the outputs of the second reconfigurable connection modules being connected in series to one another and the outputs of the third reconfigurable connection modules being connected in series to one another;
each reconfigurable connection module comprising electronic switches selectively controllable so that three connections can be made according to the control of a control device:
a direct connection wherein the voltage supplied to the input of the reconfigurable connection module is transferred to its output with the same polarity;
a bypass connection wherein the output of the reconfigurable connection module is short-circuited and the output voltage at the module is substantially equal to zero;
a reverse connection wherein the voltage supplied to the input of the reconfigurable connection module is transferred to its output with reversed polarity;
said control device being configured to cyclically control, for each reconfigurable connection module in successive instants a direct connection, a bypass connection and a reverse connection;
said control device being configured to control, for each connection module belonging to the first/to the second and to the third plurality, a time span of the bypass connection that increases between a first module of the series towards the last module of the series, so that the total voltage present at the ends of the series of modules that is given by the sum of the voltages present at the output of each reconfigurable connection module comprises:
an alternating component that varies by reproducing a waveform with double frequency with respect to the fundamental frequency and a residual noise; and
a direct component;
said converter being configured to add up the voltages present at the ends of the three series of first, second and third modules in series so as to cancel the double frequency alternating components that cancel one another out and maintain only the sum of the direct components that produce a smoothed output voltage at the converter.
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