A low power consumption induction heating power control system

Abstract

The invention discloses a low-power-consumption induction heating power control system, which is characterized in that an H-bridge load driving circuit is formed by four insulated gate bipolar transistors, and the third insulated gate bipolar transistor and the fourth insulated gate bipolar transistor are conducted in turn to form an LC series resonance current loop; the power can be adjusted by changing the time length of energy supplementation of the first insulated gate bipolar transistor and the second insulated gate bipolar transistor, and the resonant frequency of the LC series resonancecurrent loop is not affected, so that the working frequency of the LC series resonance current loop can be in an LC resonant state; the conduction points of the four insulated gate bipolar transistors are all near current zero crossing, the generated switching power consumption is very small, and the switching loss is reduced by three fourths compared with frequency modulation and power regulation, so that the area of the cooling fin is reduced; the power design margin is reduced, and the product cost is greatly reduced; and the generated harmonic waves are greatly reduced, the pollution of the harmonic waves to a power grid is greatly reduced, and the safety and the reliability of the insulated gate bipolar transistor are also improved.

Description

technical field [0001] The invention relates to an induction heating power control system, in particular to a low power consumption induction heating power control system. Background technique [0002] At present, the induction heating power control system is widely used, such as induction cooker and other fields. Its core is to use the on-off of the electromagnetic induction coil and the power switch tube to form an LC series resonant current loop. The power switch tube is more commonly used as an insulating barrier. bipolar transistors (IGBTs). The insulated gate bipolar transistor is a compound full-control voltage-driven power semiconductor device, which has the advantages of high input impedance of MOSFET and low conduction voltage drop of GTR. The saturation voltage of GTR is low, the carrying current density is large, but the driving current is large; the driving power of MOSFET is small, the switching speed is fast, but the conduction voltage drop is large, and the ...

AI Technical Summary

Problems solved by technology

[0003] It is impossible to ensure that the insulated gate bipolar transistor is turned on and off near the current zero crossing, resulting in high power consumption. In order to fully dissipate heat from the insulated gate bipolar transistor, a relatively large heat sink is required; in order to ensure that the insulated gate bipolar transistor The safety and reliability of the insulated gate bipolar transistors have a large power design margin and high cost; the generated harmonics are large and the pollution to the power grid is large

Images