A flexible power supply equipment for AC electric arc furnace

Abstract

The invention provides an AC electric arc furnace flexible power supply device, which adopts AC-DC-AC flexible power supply mode, uses the cooperation of rectifiers and inverters, changes the AC power of the grid through AC-DC-AC, and outputs AC power with adjustable voltage and frequency to feed the arc. Furnace power supply. Among them, the DC power converted by the rectifier is used to charge and discharge the capacitor of the inverter, and a DC link is introduced. The capacitor can isolate the load and the grid, so that the reactive power and harmonic current generated on the load side will not be transmitted to the grid, solving the problem of reactive power and power grid. Harmonic current is injected into the grid, causing grid pollution, so that the grid side no longer needs to configure reactive power compensation and filtering equipment. In addition, the adjustment of the arc current is realized through the inverter, so that the adjustment speed of the arc current is fast, the stability of the arc current is improved, the efficiency of electric energy transmission is improved, the loss of the system is reduced, and the smelting cycle is effectively shortened.

Description

technical field [0001] The invention relates to the field of power supply, in particular to flexible power supply equipment for an AC electric arc furnace. Background technique [0002] The AC electric arc furnace is mainly used for the smelting of scrap steel, and its power supply system is as follows: figure 1 As shown, the electric power of the power grid is reduced to the low voltage required for smelting (for example, 35KV / 1.5KV) through the series reactor 101 and the electric furnace transformer 102, and the current after the step-down passes through the short network 103 (water-cooled cable and its accessories, etc.) Entering the three-phase electrode 100, an arc current is generated in the electric arc furnace 105 for metal smelting. During the smelting process, the stability of the arc current during the smelting process is controlled and the smelting efficiency is improved through the adjustment of the electrode position and the step-by-step voltage regulation of ...

AI Technical Summary

Problems solved by technology

[0007] In view of this, the embodiment of the present invention provides an AC electric arc furnace flexible power supply equipment, which adopts the AC-DC-AC flexible power supply mode to solve the problem of harmonic pollution caused by the injection of harmonic current into the grid, so that the grid side no longer needs to configure reactive power compensation equipment , thereby reducing the cost of the electric arc furnace power supply system

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