The reason why DC electric arc furnace saves 15% power compared with AC electric arc furnace

March 09, 2024

The reason why our DC electric arc furnace saves 15% power compared with AC electric arc furnace

DC electric arc furnace, submerged arc furnace	AC electric arc furnace, submerged arc furnace
1.Natural power factor is as high as 0.95~0.98. In the working state, no matter the power size, no reactive power compensation device, the natural power factor of the equipment is always above 0.95, and the constant power factor is realized. The efficiency of converting electric energy into heat energy is high, and the effect of saving electricity is achieved. Save 15% power consumption than AC furnace.	1.The natural power factor is about 0.7~0.8, it is necessary to increase the reactive power compensation device and increase the power factor to 0.9. Increasing the reactive power compensator requires additional equipment cost, and the reactive power compensator itself will increase the equipment failure rate and power consumption, and increase the production cost.
2. There is no eddy current in the short network circuit of DC circuit, it will not produce eddy current heating phenomenon and avoid wasting electric energy.	2.AC circuit, due to the existence of alternating current, alternating magnetic field is produced in the short network circuit, and then eddy current is produced, which makes the short network circuit heat up, thus wasting part of electric energy.
3. DC current has no skin effect, the short network circuit can pass through larger current under the same cross section area, the conductor utilization ratio is high, the calorific value is small, and the heat loss is low.	3.AC itself has skin effect. The internal current distribution of the electrified conductor in the AC circuit is uneven, and the current is concentrated in the "skin" part of the electrified conductor, that is, the thin layer on the outer surface of the electrified conductor. The closer the conductor surface, the greater the current density. As a result, the area utilization ratio of the electrified conductor is reduced, and the heating is serious, which leads to the increase of electricity consumption.
4. DC has zero-zero characteristics and no polarity.The change is only a weak change, so the DC arc is more stable than the AC arc.In terms of flash intensity, it is only 20% of the AC furnace, and the impact on the power grid is much smaller than that of the AC furnace, and there is no odd harmonic interference to the power grid of 3,5,7,11,13.	4.Alternating current passes 100 times per second, that is, there are 100 times of arc initiation, arc extinguishing, re-starting and re-extinguishing every second. The problem of strong voltage flicker leads to the instability of AC arc light, harmonic distortion, voltage and current out of phase. At the same time, harmonic pollution is produced, and the 2nd and 4th even harmonics coexist with the 3rd ,5th, 7th odd harmonics, which exceed 20%~30% of the national standard, which makes the voltage distortion more complicated. And serious harmonics will cause electrical components to heat, waste electricity.