Compared to parallel inverters, thyristor series inverters

Compared with parallel inverters, thyristor series inverters have more advantages:

1. The current IL flowing through the inductor in the series inverter circuit is close to the active current, so Il is very small. The electrical loss caused by Il in the inductor resistance is very small. Through theoretical calculation and experimental testing, the electrical efficiency of the induction furnace can reach as high as 97%, and the series inverter induction furnace can save more than 10% of electricity.

2. The series inverter circuit can maintain full power throughout the entire process from cooling to casting, greatly improving operational efficiency. The melting rate is the highest.

3. The series inverter circuit requires a constant voltage source as the input and adopts a large capacity Cd filter. Firstly, the three-phase power frequency input current is kept sinusoidal, and the intermediate frequency current is completely bypassed by Cd at the DC end. The power regulation of the series inverter is achieved by the inverter bridge, and the controllable rectification angle is at zero degrees without any rectification or commutation gaps, which has no interference to the power grid.

4. The three-phase rectifier bridge maintains a zero angle during operation. The DC voltage is at its maximum value. The high-capacity CD is directly connected to the DC end, automatically maintaining the power factor of the grid above 0.97.

5. The startup success rate is 100%, and since the current flowing through the inverter thyristor is a sine wave, there is no issue with the thyristor turning on or off. The inverter will not fail to convert and there is no startup issue.