INDUCTION HEATING DEVICE AND METHOD FOR CONTROLLING INDUCTION HEATING DEVICE Russian patent published in 2007 - IPC H02M7/521 H05B6/06 

FIELD: converter engineering; induction-heating of metals and alloys.

SUBSTANCE: proposed device has DC voltage supply, filter choke, 2n inductor sections, 2n capacitors, 4n controlled valves, where n is natural number, and switch; controlled valves are pairwise cumulatively interconnected in series, through their extreme DC leads they are interconnected in parallel, and connected in forward direction through filter choke in parallel with DC voltage supply; all inductor sections, including first and last ones, are interconnected in series and connected through series-interconnection points to cumulative series-connection points of controlled valve pairs; all inductor sections are magnetically intercoupled, each next section being wound in reverse direction to preceding one and shorted out by means of separate capacitor; finishing lead of last inductor section is connected to first lead of switch whose second lead is connected to first lead of inductor first section. Inverter valves are controlled so that reverse-polarity voltages are set up across adjacent inductor sections which, along with oppositely wound adjacent sections, afford resultant magnetic flux equal to sum of fluxes from each inductor section; maximal electric potential of inductor to grounded magnetic circuit or to grounded body being heated does not exceed that across one inductor section irrespective of their quantity. To this end two antiphase enabling-pulse trains are generated of which first train affords flow of first half-wave current through all inductor sections from start to finish of these sections; second pulse train provides for second half-wave current flow through all inductor sections from finish to start of these sections. In order to prevent AC current flow through last inductor section, switch connecting extreme lead of last section to first lead of first section is opened.

EFFECT: enhanced quantity of inductor sections without raising its potential to grounded magnetic circuit or to grounded body being heated above potential across one section at only four controlled valves per every two sections.

3 cl, 2 dwg