1. The current I flowing through the inductor in the series inverter circuit is close to the active current, so I is very small, and the electrical loss caused by I in the inductor resistance is very small. Through theoretical calculation and experimental detection, the power factor of the induction furnace can reach 0.98-1, and the induction furnace with series inverter can save more than 10%.

2. Series inverter circuit can achieve 1250 from cold material to forging temperature. C. The whole process can maintain full power, greatly improve the operation efficiency and high melting rate.

3. The series inverter circuit requires that the input is a constant voltage source and adopts high-capacity CD filtering. Firstly, the three-phase power frequency input current maintains a sine wave, and the intermediate frequency current is all bypassed by CD at the DC end. The power regulation of the series inverter is realized in the inverter bridge, the controllable rectifier a angle is zero, there is no rectifier commutation gap, and there is no interference to the power grid.

4. The a angle of three-phase rectifier bridge is zero in operation That is, the DC voltage is the maximum Large capacity CD is directly connected to the DC terminal to automatically maintain the power factor of the power grid above 0.98-1.

5. The startup success rate is 100%. Since the current flowing through the inverter thyristor is a sine wave, there is no problem of thyristor on and off That is, the inverter will not fail, and there is no startup problem.