IGBT super-audio power supply for induction heating

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IGBT super-audio power supply for induction heating [Copy link]

1 Introduction

Induction heating is the direct heating of the workpiece. It has the advantages of high efficiency, good operating conditions, easy temperature control, small metal burning loss, and no need for preheating.

The power electronic devices used in traditional induction heating equipment are electron tubes and fast thyristors. Electron tubes have high voltage, poor stability, strong radiation, and low efficiency, and are on the verge of being eliminated, but they have high frequency and high power, so they still have a place in the market. Fast thyristors are the main force of current applications. They have high voltage resistance, large current, and strong resistance to overcurrent and overvoltage. However, they can only work below 10,000 Hz, which limits their scope of use.

IGBT is a composite power device that combines the advantages of bipolar power transistors and power MOSFETs. It has voltage-type control, large input impedance, low drive power, simple control circuit, low switching loss, fast on-off speed, high operating frequency, and large component capacity. It not only reaches frequencies that thyristors cannot reach (above 60kHz), but is also gradually replacing fast thyristors. IGBT has been widely used in foreign 1kHz to 80kHz induction heating, which is the development direction of induction heating power supplies. Figure 1 shows the application of various power devices abroad. 2 IGBT power supply structure and working principle