(1) Medium frequency induction heating furnace is a medium frequency induction melting furnace with series resonance type. Its inverter device is a high power thyristor. It is mainly used for melting carbon steel, alloy steel, cast steel and non-ferrous metals. It has the advantages of fast melting speed, energy saving and high harmonic pollution.

(2) The medium frequency induction heating furnace is a kind of constant power output power source, which can reach the full power output with a few materials, and has always been unchanged, so the melting speed is fast; some inverters are selected for series resonance, and the inverter voltage is high.

(3) The medium frequency induction heating furnace can save 15%-25% energy compared with the traditional parallel thyristor intermediate frequency power supply. The main reasons for energy saving are as follows:

A, high inverter voltage, small current, small line loss, this can save about 15% energy, medium frequency induction heating furnace intermediate frequency power supply inverter voltage is 2800V, while the traditional thyristor intermediate frequency power supply inverter voltage is only 750V, small current Nearly 4 times, the line loss is greatly reduced.

B. The power factor is high, the power factor is always greater than 0.98, and the reactive power loss is small. This is somewhat 3%-5% higher than the thyristor intermediate frequency power supply. Because the intermediate frequency power supply of the intermediate frequency induction heating furnace adopts the semi-controlled rectification method, the rectification some does not adjust the conduction angle of the thyristor, so the power factor of the whole operation process is always greater than 0.98, and the power loss is small.

C, furnace heat loss is small, because the medium frequency induction heating furnace medium frequency power supply can be about 15 minutes faster than the equal power thyristor medium frequency power supply. The heat lost in the furnace mouth can account for 3% of the whole process in 15 minutes. This is somewhat more energy efficient than the thyristor IF.

(4) High-order harmonic disturbance: The high-order harmonics are mainly derived from the glitch voltage of the thyristor attack when rectifying some voltage regulation, which will seriously pollute the power grid, causing other equipments to fail to operate normally, and the intermediate frequency induction heating furnace has some rectification of the intermediate frequency power supply. The semi-controlled rectification method is adopted. The DC voltage always operates at the highest level and does not adjust the conduction angle. Therefore, it does not attack high-order harmonics, does not pollute the power grid and transformer, does not generate heat, and does not disturb other electronic equipment in the factory. .

(5) Constant power output: The thyristor intermediate frequency power supply adopts voltage regulation and power adjustment, while the intermediate frequency induction heating medium frequency power supply selects frequency modulation power, which is not affected by the amount of furnace material and the thickness of the furnace lining, and adheres to constant power output throughout the smelting process. Especially when producing non-magnetic materials such as stainless steel, copper, aluminum, etc., it is more advantageous, the melting speed is fast, the burning of the charge of the charge is less, and the casting cost is lowered.