Be familiar with induction heating of electric heating
The induction heating of an electric heater is a thermal effect formed by an induced current (eddy current) produced by a conductor in an alternating electromagnetic field, so that the conductor itself is heated. According to the requirements of different heating process, the frequency of AC power used in induction heating has power frequency (50~60 Hz), intermediate frequency and high frequency (higher than 10000 Hz).
Frequency power supply is usually used in industrial AC power supply, most countries in the world power frequency is 50 hz. The voltage applied by induction heating to the induction device must be adjustable. According to the power of heating equipment and the size of the power supply network, power supply can be supplied by a high-voltage power supply (6~10 kV) through the transformer, or the heating equipment can be directly connected to the 380 volt low voltage power grid.
Intermediate frequency power supply uses thyristor frequency converter. The intermediate frequency power supply utilizes the thyristor to convert the AC power frequency into direct current, and then converts the direct current into the alternating current at the required frequency. This inverter is small in size, light in weight, noiseless and reliable in operation.
High frequency power supply is usually used to increase the voltage transformer three-phase 380 volts high voltage of about 20 thousand volts or so, and then use the thyristor or the high voltage silicon rectifier rectifier DC to AC, then the electron oscillation tube to DC power into high frequency and high voltage alternating current. High frequency power supplies have power output ranging from tens of kilowatts to hundreds of kilowatts.
An object heated by induction must be a conductor. When the high frequency AC current passes through the conductor, the conductor has a skin effect, i.e., the conductor surface current density is large, and the conductor center current density is small.
Induction heating can make the whole body evenly heated and heated on the surface. It can smelt metal; in the high frequency section, it can change the shape of the heating coil (also called inductor), and also can carry out any local heating.