DOUBLE-FREQUENCY TWO-STEP SINGLE- TO THREE-PHASE CONVERTER FOR INDUCTION HEATING AND FUSION OF METALS Russian patent published in 2010 - IPC H05B6/04 

FIELD: electricity.

SUBSTANCE: first version of the device consists of five controlled rectifiers of thyristors, two of which, the first and the second, form the first stage and with their first leads through the first input choke are connected to the first pole of a dc voltage source, the parallel first switching capacitor and active-inductive load inductor which is executed from three equal matched series sections are connected to the second leads of the first and second controlled rectifiers, and the third, fourth and fifth controlled rectifiers which form the second stage are connected with their first leads to series points of trimmer chokes of the first, second and third stages with the second, third and fourth switching capacitors in three series circuits each of which is parallel connected with one of three sections of the active-inductive load inductor, and the second leads of three additional rectifiers of the third, fourth and fifth stage are connected to the first lead of the second input choke with its second lead being connected to the second pole of the dc voltage source. According to the second version of the device, there are introduced three additional circuits each consisting of series switching capacitor and trimmer choke, and each of these circuits is also parallel connected to one of three sections of the active-inductive load inductor, thus the first leads of the sixth, seventh and eighth controlled rectifiers of the second stage with the second leads being connected to the first lead of the second input choke are connected to common junctions of the switching capacitors and the trimmer chokes of each additional series circuit. The connection of the first and second controlled rectifiers of the first stage in both versions of the device provides the high-frequency electromagnetic field to be generated, while the connection of the third, fourth and fifth controlled rectifiers of the second stage in the first version of the device and the connection of the third, fourth, fifth, sixth, seventh and eighth controlled rectifiers of the second stage in the second version of the device provides the three-phase low-frequency electromagnetic field to be generated.

EFFECT: simultaneous generation of both high-frequency and low-frequency electromagnetic fields, and simplification.

2 cl, 8 dwg