Series resonance injection type hybrid active filter with convertible structure

Abstract

The invention discloses a series resonance injection type hybrid active filter with a convertible structure. The series resonance injection type hybrid active filter comprises a passive filter bank, an injection branch and an active filter; the injection branch is composed of a capacitor C1, an inductor L1 and a capacitor CO; the output end of the active filter APF is connected in parallel with a fundamental wave series resonance circuit through a coupling transformer to form an injection type active filter; R1 and R2 are switching converters and are responsible for controlling conversion of a hybrid active filter structure; and two ends of the injection branch are respectively connected in series with the passive filter bank through R1 and R2. According to the invention, different working modes can be switched according to different stages of operation of an electric arc furnace, the filter structure in different modes can have good treatment capability on load harmonics in corresponding smelting stages of an electric arc furnace, fundamental wave active power loss is reduced to a certain extent, the comprehensive performance of the hybrid active filter is improved, and the service life of the hybrid active filter is prolonged.

Description

technical field [0001] The invention relates to the field of power filtering, in particular to a series resonant injection type hybrid active filter with switchable structure. Background technique [0002] With the development of society, the demand for steel is increasing. In the steelmaking industry, electric arc furnace steelmaking occupies a large proportion. The development of electric arc furnace technology has led to more and more electric arc furnaces being put into large-scale steel production, and a series of impacts on the power supply side have become more and more obvious. The electric arc furnace uses the principle of alternating current arc heating for steelmaking. The irregular change of the arc length leads to the non-linearity of the arc resistance, which causes the current to be distorted and generates harmonic current. The harmonic current flows into the power supply system and acts on the system. Impedance, resulting in voltage distortion, the generatio...

AI Technical Summary

Problems solved by technology

Therefore, with the improvement of the electric arc furnace smelting process, the complex hybrid active filter is continued to be invested, which consumes a lot of active power and brings certain losses to the enterprise.

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