Electric cooking device and electromagnetic heating system for electric cooking device

Abstract

The invention discloses an electric cooking device and an electromagnetic heating system used for the electric cooking device, wherein the electromagnetic heating system includes: a resonance module; a switch module; a drive module; a current sampling module, which is used to collect the current flowing into the switch module, and Generate the first detection signal according to the current; the overcurrent detection module filters out the inrush current in the first detection signal when the switch module is turned on, and outputs the first comparison signal according to the first detection signal; the control module is used to output the driving signal to the driving module, so as to drive the switching module on / off through the driving module, and stop outputting the driving signal when judging the overcurrent of the switching module according to the first comparison signal, so as to turn off the switching module. The system can monitor the current flowing through the switch module, and turn off the switch module when the switch module is overcurrent, so as to protect the switch module from overcurrent, and can filter the inrush current when the switch module is turned on, so as to prevent the inrush current Trigger false protection.

Description

Technical field [0001] The present invention relates to the field of electrical techniques, and Background technique [0002] Electric cooking artifacts, electric cooking, electric rice cooker, electric pressure cooker, etc. Take 10A. The current here is calculated according to the frequency of 50 Hz, however, the electromagnetic heating system induces the operating frequency of about 20 to 40 kHz, and the maximum instantaneous current of the switch tube in a single cycle can reach 40-50A. Further, if the voltage of the collector electrode is higher than zero volts before the switch is turned on, it is necessary to force a resonant capacitor to charge in an electromagnetic heating system. Since the switch of the switching tube, the voltage mutation of the resonant capacitance, therefore, the switch The moment of tube is turned on, there will be more than 60A transient impact current flow through the switch tube. [0003] It is because of the presence of the impact current describ...

AI Technical Summary

Problems solved by technology

The average value of the current here is calculated according to the frequency of the input alternating current of 50Hz. However, the operating frequency of the electromagnetic heating system during induction heating is about 20~40kHz, and the maximum instantaneous current of the switching tube in a single cycle can reach 40-50A. In addition, if the voltage of the collector of the switch tube is higher than zero volts before it is turned on, it is necessary to force the resonant capacitor in the electromagnetic heating system to be charged. Due to the on-off of the switch tube, the voltage of the resonant capacitor will change suddenly. Therefore, the switch At the moment when the tube is turned on, there will be a transient impact current of more than 60A flowing through the switch tube.

[0003] It is precisely because of the existence of the above-mentioned inrush current that the electromagnetic heating system in the related art does not monitor and protect the current of each working cycle of the switch tube, so that the switch tube is easily damaged, which in turn leads to poor reliability of the electromagnetic heating system

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