|
Item |
SCR MF power supply |
IGBT MF power supply |
|
Range |
160 ~ 4000 kW |
50 ~ 4400 kW |
|
Power factor |
Rated power is close to 0.90
Power factor going down when the power is reduce. |
close to 1.0 |
|
Harmonic interfere |
The grid have a greater harmonic interference |
Be able to effectively eliminate harmonic3銆5銆7銆9銆11. |
|
Conversion Efficiency |
Middle power is the same. Big power is lower. |
Middle power is the same. Big power is higher. |
|
Load adaptability |
Normal |
Big |
|
Constant power output capability |
Low power output when the start running the raw material. Improved inverter control at close to constant power operation, but the complicated of control. |
Keep the constant power running during the whole melting process. Easy to control. |
|
Frequency range |
Maximum 2500Hz
Mainly used for induction melting and holding. |
Maximum 100 kHz
Induction melting and holding, but also used heating and quenching |
|
Stability |
High. MF current itself engender a loop, SCR must have the current, anti-interference ability is poor |
Hihger. MF current through the IGBT engender a loop.IGBT is voltage control device. Anti-interference ability is strong |
|
Device Over-current capacity and protection |
The over-current capacity is big. Protection circuit is simple, maintenance is difficult |
The over-current capacity is small. Protection circuit is complicated. High require for the technique, easy to maintenance. |
|
Power supply transformer allowance requirements |
Larger. transformer capacity of Power supply is 1.25 times maximum output MF power supply |
Small. transformer capacity of Power supply is 1.1 times maximum output MF power supply |
|
Possibility of power sharing. |
Impossible |
Possible |
|
Spare part cost |
lower |
Higher |
