INDUCTIVE HEATING DEVICE AND ITS CONTROL PROCESS Russian patent published in 2004 - IPC

FIELD: converter engineering; power inverters of metal inductive heating and smelting devices.

SUBSTANCE: device has n identical inverter cells 1-1, 1-2, 1-3, where n is number of inductor sections. Each cell is separately controlled. Control pulse repetition rate is shaped to be equal to inherent resonant frequency of parallel high-frequency oscillatory circuit of inverter cell or it is tuned away from its resonant frequency. Inverter cell has half-bridge circuit set up of controlled switches 6, 7 and diodes 8, 9. Serial and parallel correction of inductor flux density is made in each inverter cell at low- and high-frequency components of inductor section current frequency. High-frequency oscillations are generated in the form of sine wave with center line varying by low-frequency signal mechanism with aid of half-bridge switches 6, 7 and diodes 8, 9. In addition center line of sine wave is offset relative to adjacent inverter cell through desired phase angle. As a result high- and low-frequency currents are generated simultaneously in inductor sections 2-1, 2-2, and 2-3.

EFFECT: enlarged functional capabilities due to independent generation of high- and low-frequency signals and separate control of these signals.

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