摘要 |
<p>PCT No. PCT/FR87/00166 Sec. 371 Date Jan. 19, 1988 Sec. 102(e) Date Jan. 19, 1988 PCT Filed May 20, 1987 PCT Pub. No. WO87/07455 PCT Pub. Date Dec. 3, 1987.A frequency converter is provided for the power supply of an asychronous motor, comprising: a rectifier bridge (11) connected to a multiphase network and to an intermediate DC circuit (12); an inverter (13) comprising three pairs of static switches (T1-T6) connected in a Graetz bridge; characterized by; a means (21) for reading the current associated with the intermediate circuit (12) and elaborating an image signal of the reverse circuit and delivering an image signal of the current in this circuit; a stabilization control circuit (22) connected to said means (21) and delivering a reverse current excess signal (ST) when the signal (Id) exceeds an adjustable threshold; and a means (25) for reducing the output voltages of the inverter, and adapted for modifying the modulated pulses, this means being controlled by the output signal (ST) of the stabilization control circuit (22).</p> |