Induction generator for induction heating devices and a method for the operation of an induction generator for induction heating elements

摘要

An induction generator is connected to a three-phase mains. The induction generator includes a control unit (10) connected to a current transformer (38), on one (L1) of the lines (L1, L2, L3) of the three-phase mains. The induction generator includes a number of power sections (26, 28, 30, 32, 34, 36). Each power section (26, 28, 30, 32, 34, 36) supplies one of the induction coils (40, 42, 44, 46, 48, 50). A control unit (10) estimates and corrects harmonic distortions of the mains current via the current transformer (38). The power transferred to a heated object as a function of the frequency is stored in a memory of the control unit (10), so that the heated object is identifiable by its frequency-power characteristic. The frequency spectrum of the transferred power related to a harmonic distortion in the line (L1) is stored in the memory (10) if the distortion exceeds a predetermined limit. The harmonic distortions are corrected by the control unit (10) if a heated object with the frequency-power characteristic related to the harmonic distortion is detected.