How to choose inverter thyristor for induction melting furnace?
1) Select according to the operating frequency range of the induction melting furnace;
The frequency is 100HZ---500HZ and the selected turn-off time is 20µs-45µs KK type thyristor.
The frequency is 500HZ---1000HZ and the selected turn-off time is 18μs-25μs KK type thyristor.
The frequency is 1000HZ---2500HZ and the selected turn-off time is 12μs-18μs KK type thyristor.
KKG-type thyristor with a frequency of 2500HZ---4000HZ and a selected turn-off time of 10µs-14µs.
The frequency is 4000HZ---8000HZ, and the selected turn-off time is 6μs—9μs KA type SCR.
2) Select according to the output power of the induction melting furnace;
According to the theoretical calculation of the parallel bridge inverter circuit, the current flowing through each thyristor is 0.455 times the total current. Considering that enough space is left, a thyristor with the same size as the rated current is usually selected.
The selected current 300A/1400V thyristor with power between 50KW and 100KW. (380V phase-in voltage)
The selected current 500A/1400V thyristor with a power of 100KW-250KW. (380V phase-in voltage)
The selected current 800A/1600V thyristor with a power ranging from 350KW to 400KW. (380V phase-in voltage)
The selected current 1500A/1600V thyristor with power between 500KW and 750KW. (380V phase-in voltage)
The selected current 1500A/2500V thyristor with power between 800KW and 1000KW. (660V phase-in voltage)
The selected current 2000A/2500V thyristor with a power of 1200KW-1600KW. (660V phase-in voltage)
The selected current 2500A/3000V thyristor with power between 1800KW and 2500KW. (1250V phase-in voltage)
