IGBT is a new type of switching device. It has a fast switching speed, and the control signal is turned on. The control signal is cut off, which facilitates control, reduces the on-voltage and reduces power consumption. The maximum current of the IGBT only needs to be twice the rated current, and the impact resistance is poor. Thyristor is a traditional switching device with large control power and strong impact resistance. Are IGBT electric furnaces more power efficient than SCR electric furnaces? We can see whether it is power saving through the following calculations. For example, a 1 ton electric furnace has a power of 500KW, a phase voltage of 380V, an IGBT electric furnace with a power factor of 0.98, a DC current of 928A, and the power consumed by the four IGBTs is [1V (IGBT turn-on voltage drop) X 928A / 2] X 4 = 1856W = 1.856KW; the power factor of the SCR electric furnace is 0.93, the DC current is 977A, and the power consumed by the thyristor is: [1.2V (thyristor conduction voltage drop) X977A / 2] X 4 = 2344W = 2.344KW, it can be seen that the power consumed by the IGBT is 21% less than the power consumed by the thyristor. Therefore, it saves power, but the maintenance cost is high, the technology is not matured with thyristor, and the failure rate will be high if the furnace has a large tonnage, depending on the situation of your company, but the product price and maintenance cost are high, the performance is not as mature as thyristor, power It's not suitable for bigger. Generally do not buy IGBT, only universities and colleges, laboratories, etc. will consume, private bosses do not need to consume.
It is concluded that the IGBT electric furnace saves 21% of the electricity than the thyristor electric furnace, which is wrong. We continue to calculate that the power consumed by the IGBT is a percentage of the total power of 1.856KW / 500KW = 0.003712 = 0.3712%; The percentage of power is 2.344KW / 500KW = 0.004688 = 0.4688%. With the above accounting data, it can be seen that under the same conditions, the IGBT electric furnace saves 0.0976% of the electricity than the SCR electric furnace, which can be neglected. If other conditions are changed, the IGBT electric furnace uses a series inverter and saves power by advancing the intermediate frequency voltage. That is another matter. The SCR electric furnace can advance the intermediate frequency voltage by 2 times the voltage. Because the SCR's withstand voltage and current are much higher than the IGBT device, the SCR electric furnace can choose high phase voltage and high intermediate frequency voltage. The plan is reasonable and it can save more power than the expensive IGBT electric furnace.