Frequency modulation method for full-bridge inverter circuit

Abstract

The invention relates to electronic circuit technologies, in particular to a frequency modulation method for a full-bridge inverter circuit. According to the frequency modulation method for the full-bridge inverter circuit, a reverse conducting type IGBT switching tube S1, a reverse conducting type IGBT switching tube S2, a reverse conducting type IGBT switching tube S3 and a reverse conducting type IGBT switching tube S4 are used for forming the full-bridge inverter circuit, a full-bridge modulation mode is adopted when the output power of the full-bridge inverter circuit ranges from 56% to 100%, an asymmetric frequency modulation mode is adopted when the output power of the full-bridge inverter circuit ranges from 25% to 56%, a half-bridge modulation mode is adopted when the output power of the full-bridge inverter circuit is smaller than 25%. The frequency modulation method for the full-bridge inverter circuit has the advantages that through a segmented power modulation mode, the power factor and efficiency of devices are greatly improved. The frequency modulation method is especially applicable to full-bridge inverter circuit frequency modulation.

Description

technical field [0001] The invention belongs to electronic circuit technology, and in particular relates to a frequency modulation method for a full-bridge inverter circuit. Background technique [0002] In the application of induction heating power supply, the traditional voltage-type full-bridge inverter power adjustment method is symmetrical frequency modulation power adjustment. When the switching frequency of the inverter increases from the natural resonant frequency of the equipment, the output power of the equipment will decrease. Frequency modulation and power modulation have the advantages of being simple and easy to operate, but their disadvantages are also obvious. When the power applied to the fixed load is lower, the switching frequency of the inverter circuit needs to be higher, and the power factor and efficiency are lower. Existing solutions such as phase-shift power modulation and pulse density power modulation control methods are quite complicated to operat...

AI Technical Summary

Problems solved by technology

Frequency modulation and power modulation have the advantages of being simple and easy to operate, but its disadvantages are also obvious. When the power applied to the fixed load is lower, the switching frequency of the inverter circuit needs to be higher, and the power factor and efficiency are lower.

Existing solutions such as phase-shift power modulation and pulse density power modulation control methods are quite complicated to operate. The efficiency of the lagging arm is poor when the phase-shift power modulation outputs low power. The pulse density power modulation has large noise and poor heating. uniform problem

Chopper power regulation can solve the power output problem under various loads, but chopping power regulation needs to add a lot of extra equipment, making the control more complicated, increasing the cost and reducing the efficiency of the system

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