The application of Mosfet, IGBT and vacuum triode in industrial induction heating machine (furnace)

Modern Induction Heating Power supply technology mainly relies on three types of core power devices: MOSFET, IGBT and vacuum triode, each of which plays an irreplaceable role in specific application scenarios. MOSFET has become the first choice in the field of precision heating due to its excellent high-frequency characteristics (100kHz-1MHz), and is particularly suitable for low-power and high-precision scenarios such as jewelry melting and electronic component welding. Among them, SiC/GaN MOSFET has increased the efficiency to more than 90%, but its power limit (usually <50kW) restricts its application in large equipment.

In the field of medium-frequency and high-power (1kHz-100kHz), IGBT has shown a strong competitive advantage. As the core device of industrial melting furnaces and metal Heat Treatment production lines, IGBT modules can easily achieve MW-level power output. Its mature technology and excellent cost-effectiveness make it a standard choice for processing materials such as steel and aluminum alloys. With the introduction of SiC technology, the operating frequency of the new generation of IGBT has exceeded 50kHz, further consolidating its market dominance in the medium-frequency band.

In ultra-high-frequency and high-power scenarios (1MHz-30MHz), vacuum triodes still maintain an unshakable position. Whether it is special metal smelting, plasma generation, or broadcast transmission equipment, vacuum triodes can provide MW-level stable power output. Its unique high-voltage resistance and simple drive architecture make it an ideal choice for processing active metals such as titanium and zirconium, despite its low efficiency (50%-70%) and high maintenance costs.

The current technological development shows a clear trend of convergence: MOSFET continues to penetrate into the high-frequency and high-power fields through SiC/GaN technology; IGBT continues to expand the working frequency band through material innovation; while vacuum tubes face competitive pressure from solid-state devices while maintaining their ultra-high frequency advantages. This technological evolution is reshaping the industrial landscape of induction heating power supplies.

In actual selection, engineers need to comprehensively consider the three major factors of frequency, power and economy: MOSFET is preferred for high-frequency and low-power, IGBT is selected for medium-frequency and high-power, and vacuum triodes are still needed for ultra-high frequency and high power. With the advancement of wide-bandgap semiconductor technology, this selection standard may change, but in the foreseeable future, the three types of devices will continue to play an important role in their respective areas of advantage, and jointly promote the development of induction heating technology towards a more efficient and precise direction.