Power control method of electromagnetic heating device

Abstract

The invention provides a power control method of an electromagnetic heating device. The method comprises the following steps: judging whether target heating power is greater than a preset value; adjusting a switching circuit to control a rectifying circuit to output full-wave rectified waveform when the target heating power is greater than the preset value, and enabling the controller to send outa control signal to drive the connection of the power tube, thereby enabling a resonance circuit to work; when the target heating power is less than the preset value, adjusting the switching circuit to control the rectifying circuit to output half-wave rectified waveform, and then enabling the controller to send out the control signal to drive the connection of the power tube at the subsequent t1moment, thereby enabling the resonance circuit to work, wherein the t1 moment is the moment without waveform output of the half-wave rectified waveform, or the moment after the half-wave rectified waveform at least experiences a half-wave cycle without waveform. The IGBT is turned on at zero voltage or low voltage when the small power heating is guaranteed, the noise is reduced, and the service life of the IGBT is improved.

Description

technical field [0001] The invention relates to the technical field of kitchen appliances, in particular to a power control method for an electromagnetic heating device. Background technique [0002] The heating principle of the electromagnetic heating device is that the electromagnetic heating device generates an alternating magnetic field, and the ferromagnetic material placed in the alternating magnetic field generates heat by itself due to induction. Electromagnetic heating is more common in cooking utensils, such as induction cooker, IH rice cooker, etc. Cooking utensils using electromagnetic heating are popular among users because of their high thermal efficiency, cleanliness, and convenience. Electromagnetic heating cooking utensils need to use IGBT alternating on and off to achieve electromagnetic resonance. When heating with high power, the IGBT works well, but when heating with low power, there is a relatively high voltage at both ends of the IGBT. The low power s...

AI Technical Summary

Problems solved by technology

During the period of T1, the alternating current charges the capacitance of the circuit, so that the voltage across the IGBT is stable at V1, and its theoretical value is 311V. When the IGBT is turned on at this voltage, a large current will be generated, which will generate noise and affect users. At the same time, the service life of the IGBT will be greatly reduced due to the large turn-on current of the IGBT

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