Power supply device for coreless induction furnace, has induction coils controlled in phase-in and phase-shift manner, where coils are connected in parallel by mechanically operatable contactors and by switches during in-phase operation

摘要

The device has parallel-compensated induction coils (2a-2c) fed with adjustable frequency by inverters (1a-1c), where the induction coils are controlled in a phase-in and phase-shift manner. The induction coils are connected in parallel by mechanically operatable contactors (5a-5d) and by thyristor switches during the in-phase operation, where the phase angle is 120 degrees during phase-shift control of the induction coils. The parallel-compensated induction coils surround goods e.g. metals, to be inductively heated and are arranged displaceably to each other.