CN-122002657-A - Low electromagnetic noise's lost wave mode electromagnetism stove

Abstract

The invention provides a low electromagnetic noise wave loss type induction cooker, which comprises an LC resonance circuit, an IGBT module, an MCU unit, a grid drive IC and a pot detection circuit, wherein the MCU unit is connected with the IGBT module through the grid drive IC, the drive voltage range of the IGBT module is 9-18V, the grid drive IC has various power supply modes in 5-18V drive voltage, a power judgment module is arranged in the MCU unit, when the power judgment module detects that the working power of the induction cooker is lower than 50% of the maximum power, the MCU unit controls the grid drive IC to switch to the 9V power supply mode, when the power judgment module detects that the working power of the induction cooker is greater than or equal to 50% of the maximum power, the MCU unit controls the grid drive IC to switch to the 18V power supply mode, and when the pot detection circuit works, the MCU unit controls the grid drive IC to switch to the 9V power supply mode. According to the low electromagnetic noise wave-loss mode electromagnetic oven provided by the invention, the flexible switching of the driving voltage is realized through the design of the wide-voltage IGBT selection and the special driving control module, the noise generation is restrained from the source, and the use experience is improved.

Inventors

• CAO YOULIANG
• WANG ZHE
• Deng Wenlai

Assignees

• 广东甜美见舟电器有限公司

Dates

Publication Date

20260508

Application Date

20260119

Claims (5)

1. 1. The wave-loss type induction cooker with low electromagnetic noise is characterized by comprising an LC resonance circuit, an IGBT module, an MCU unit, a grid drive IC and a pan detection circuit, wherein the IGBT module is connected in series in the LC resonance circuit; the pan detection circuit is connected with the LC resonance circuit and is used for detecting the state of a pan and transmitting detection signals to the MCU unit, the MCU unit is connected with the IGBT module through the grid drive IC, the drive voltage range of the IGBT module is 9-18V, and the grid drive IC has various power supply modes in 5-18V drive voltage; The power judging module is arranged in the MCU unit, when the power judging module detects that the working power of the induction cooker is lower than 50% of the maximum power, the MCU unit controls the grid driving IC to be switched to a 9V power supply mode, when the power judging module detects that the working power of the induction cooker is greater than or equal to 50% of the maximum power, the MCU unit controls the grid driving IC to be switched to an 18V power supply mode, and when the pot detecting circuit works, the MCU unit controls the grid driving IC to be switched to the 9V power supply mode.
2. 2. The low electromagnetic noise wave-loss mode electromagnetic oven according to claim 1, wherein the gate drive IC is provided with a 5V voltage stabilizing unit for supplying power to the MCU unit, and a dead time control unit is provided in the gate drive IC, and the dead time of the dead time control unit is set to 60ns.
3. 3. The low electromagnetic noise wave-loss mode electromagnetic oven according to claim 2, wherein the power supply voltage of the gate drive IC is 8-33V, and the output driving capability is +400mA/-460mA@18V.
4. 4. The low electromagnetic noise wave-loss mode electromagnetic oven according to claim 3, wherein 3.3V/5V compatible logic signal transmission is adopted between the MCU unit and the gate drive IC, and a pull-down resistor is arranged at the output end of the gate drive IC.
5. 5. The low electromagnetic noise wave-loss mode electromagnetic oven of claim 4, wherein the gate drive IC is built with an over-temperature protection unit, an under-voltage protection unit and an over-voltage protection unit.

Description

Low electromagnetic noise's lost wave mode electromagnetism stove Technical Field The invention relates to the field of electromagnetic ovens, in particular to a wave-loss type electromagnetic oven with low electromagnetic noise. Background At present, the common technical schemes in the electromagnetic heating field are mainly divided into two types, namely an LC parallel resonance type frequency conversion scheme (namely a single-tube scheme) and a half-bridge scheme in which two IGBTs of an upper arm and a lower arm are sequentially conducted. Although the half-bridge scheme has stable performance, the half-bridge scheme has the defects of high cost and high technical threshold, and is difficult to apply in a large scale in a medium-low end induction cooker product, and the single-tube LC parallel resonance type frequency conversion scheme becomes a mainstream application scheme due to the advantages of relatively simple structure, strong stability, controllable cost and the like. In order to further optimize the heating performance of the single tube scheme, the technical iteration is carried out in the industry, and the intermittent heating mode of a medium and small power section with the maximum power of less than 50% in the original single tube scheme is improved to be the wave-loss mode for heating so as to improve the heating continuity and the temperature control precision. However, after the single-tube scheme is heated in a wave-loss mode, the conventional control method has obvious technical defects that electromagnetic noise is obviously increased in the pot detection process and the wave-loss heating stage, the use experience of users is seriously affected, and the single-tube scheme is difficult to accept in the market. Disclosure of Invention In order to make up for the defects in the prior art, the invention provides the low electromagnetic noise wave-loss mode electromagnetic oven, and the flexible switching of driving voltage is realized through the design of the wide-voltage IGBT model selection and the special driving control module, so that the noise generation is restrained from the source, and the use experience is improved. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The wave-loss type induction cooker with low electromagnetic noise comprises an LC resonance circuit, an IGBT module, an MCU unit, a grid drive IC and a pan detection circuit, wherein the IGBT module is connected in series in the LC resonance circuit; the pan detection circuit is connected with the LC resonance circuit and is used for detecting the state of a pan and transmitting detection signals to the MCU unit, the MCU unit is connected with the IGBT module through the grid drive IC, the drive voltage range of the IGBT module is 9-18V, and the grid drive IC has various power supply modes in 5-18V drive voltage; The power judging module is arranged in the MCU unit, when the power judging module detects that the working power of the induction cooker is lower than 50% of the maximum power, the MCU unit controls the grid driving IC to be switched to a 9V power supply mode, when the power judging module detects that the working power of the induction cooker is greater than or equal to 50% of the maximum power, the MCU unit controls the grid driving IC to be switched to an 18V power supply mode, and when the pot detecting circuit works, the MCU unit controls the grid driving IC to be switched to the 9V power supply mode. Further, a 5V voltage stabilizing unit is arranged in the grid driving IC and used for supplying power to the MCU unit, and a dead time control unit is arranged in the grid driving IC and is set to be 60ns. Further, the power supply voltage working range of the grid drive IC is 8-33V, and the output driving capability is +400mA/-460mA@18V. Furthermore, 3.3V/5V compatible logic signal transmission is adopted between the MCU unit and the gate drive IC, and a pull-down resistor is arranged at the output end of the gate drive IC. Further, the gate driving IC is internally provided with an over-temperature protection unit, an under-voltage protection unit and an over-voltage protection unit. Compared with the prior art, the invention has the following beneficial technical effects: 1. the electromagnetic noise and the pan knocking sound in the using process of the induction cooker are remarkably reduced, namely, through the matching of the wide-voltage IGBT and the grid drive IC, 9V drive voltage is adopted in the pan detection stage and the middle-low power wave loss heating stage with the maximum power of less than 50%, the 9V drive can effectively reduce the switch stress of the IGBT and the current impact of a coil in an LC resonance circuit, meanwhile, the 9V pan detection circuit optimizes the resonance matching effect, the pan bottom vibration is restrained from the source, the electromagnetic noise and the pan knocking sound are greatly reduced, a