The working principle of an induction heating power supply is based on the induced current (eddy current loss) generated in a conductor under the influence of a high-frequency magnetic field, and the effect of the magnetic field within the conductor (hysteresis loss), which causes the conductor to heat up.
Power Conversion:
An induction heating system consists of a high-frequency power supply (high-frequency generator), wires, a transformer, and an inductor.
The high-frequency power supply first converts ordinary power (such as 220V/50Hz) into a high-voltage, high-frequency, low-current output. The frequency depends on the object being heated, but is generally around 480kHz.
Current to Magnetic Field Conversion:
A transformer converts high-voltage, high-frequency, low-current into low-voltage, high-frequency, high-current.
When this low-voltage, high-frequency, high-current flows through the inductor, a strong high-frequency magnetic field is generated around it. The greater the current, the stronger the magnetic field.
Induction heating:
When a conductor (such as a metal workpiece) is placed in a high-frequency magnetic field generated by an inductor, an induced current (eddy current) is generated inside the conductor.
As the eddy currents flow inside the conductor, heat is generated due to the resistance (eddy current loss).
Simultaneously, changes in the magnetic field also generate hysteresis losses inside the conductor, further heating it.
Applications and Optimizations:
Induction heating technology is widely used in metal heat treatment, quenching, through-heating, smelting, brazing, and other fields.
With the development of electronic technology, all-transistor high-frequency induction heating equipment has gradually replaced traditional electron tube high-frequency induction heating equipment, improving overall efficiency and energy utilization.