Arc furnace power quality controller based on programmable logic controller (PLC)

Abstract

The invention relates to an arc furnace power quality controller based on a programmable logic controller (PLC), which mainly comprises a control system and a power quality improvement system, wherein the control system consists of an industrial personal computer, a PLC and a digital signal processor (DSP); and the power quality improvement system consists of thyristor switched capacitor - thyristor controlled reactor (TSC-TCR) reactive power compensation device and an auxiliary circuit. The controller can adjust compensation parameters in real time to improve compensation accuracy according to instantaneous reactive power in combination with furnace condition information. The arc furnace power quality controller based on the PLC has the advantages that the rapid real-time compensation can be realized aiming at the change of the reactive power and the power factor, the operating cost is low and the control stability is high.

Description

technical field [0001] The invention belongs to the field of steelmaking equipment, and relates to a power quality controller for a three-phase AC electric arc furnace. The control system is composed of an industrial computer, PLC and DSP. The compensation system is a TSC TCR reactive power compensation device, which is suitable for various capacities. three-phase AC electric arc furnace. Background technique [0002] Electric arc furnace is the main equipment for modern steelmaking. With the industrial requirements of high productivity, low energy consumption, low material consumption and high environmental protection indicators, modern electric arc furnace is developing towards the direction of ultra-high power and ultra-large capacity. However, with the increase of capacity and power, power quality problems such as harmonics, voltage fluctuations and flicker, and low power factor brought about by the operation of electric arc furnaces have become more and more prominent. ...

AI Technical Summary

Problems solved by technology

[0004] SVC has a variety of structures: thyristor-controlled reactor type, which is itself a harmonic source, filters out the harmonics generated by the electric arc furnace and generates new harmonics; thyristor-controlled reactor type, which does not generate harmonics itself, but cannot realize continuous regulation

[0005] Static synchronous compensator STATCOM can quickly provide capacitive reactive power and inductive reactive power, stabilize voltage, improve system stability, and improve system dynamic performance. For large-capacity, high-power electric arc furnace systems, using STATCOM can get better Compensation effect, but this also greatly increases the cost

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