Schneider Electric Sa

Eric Bonsignour

Vinh Tung Nguyen Phuoc

This invention relates to a device for measuring currents used in a converter (1) powered by a DC power source and equipped with six switches (T1, T2, T3, T4, T5, T6) associated with diodes (D1, D2, D3, D4, D5, D6) and controlled by a control circuit (2) and a microcontroller (3), and equipped with current sensors (Su, Sv, Sw) each located between the switch and the diode associated with a lower channel, and secondly the return conductor to the DC power source supplying 'direct' signals (Isu, Isv, Isw) in phase with the currents (Ia, Ib, Ic) output from the converter, characterized by the fact that it includes means (A46, A62) of calculating an 'indirect' replacement signal (Iai) equal to the sum of two 'direct' signals (-Isu and -Isw) and a second 'indirect' replacement signal (Ici) equal to the sum of the two 'direct' signals (-Isu and -Isw) and means (Cu, Cw) for switching either a 'direct' signal (Isu or Isw) or an 'indirect' replacement signal (Iai or Ici) so as to send to the microcontroller (3) two signals reconstructed from the two phase currents (Ia* and Ic*), each composed of either the 'direct' signal (Isu or Isw) or, during the PWM steps in which the lower branch transistor is not controlled, the 'indirect' replacement signal (Iai, Ici).

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Carrieres sur Seine, France

Eric Bonsignour