Hybrid flexible power supply system of alternating current electric arc furnace and control method of

Abstract

The invention discloses a hybrid flexible power supply system of an alternating-current electric arc furnace and a control method of the hybrid flexible power supply system. The hybrid flexible power supply system comprises a main loop and a control-protection system. The main loop reduces the manufacturing difficulty and early-stage investment of key equipment, can significantly reduce the threat to the power quality of the system side and isolates the frequency impact of the extreme operation condition of the load side on the system side; the control system aims at minimizing the unit product production cost of a user side or providing auxiliary service for a system side, collects renewable energy output prediction information in the day and formulates a production and unit starting plan on the current day, and when the electric arc furnace is not produced, distributed renewable energy can be connected to a grid or stored by an energy storage device; during production of the electric arc furnace, according to output errors of renewable energy sources, a steady-state operation point is regulated and controlled in an equipment power operation domain so as to change a heating period, and a control system is used for maintaining load side control precision. The digitization level of the metallurgical process can be improved, and additional cost such as early-stage investment cost and shutdown maintenance time during operation in a next-generation electric arc furnace power supply system is reduced.

Description

technical field [0001] The invention relates to the technical fields of metallurgical technology and special load power supply and distribution, in particular to a hybrid flexible power supply system for an AC electric arc furnace and a control method thereof. Background technique [0002] In recent years, due to the accumulation of steel scrap in my country and the complete banning of intermediate frequency induction furnaces, the short-process AC electric arc furnace (EAF) will usher in a new round of development opportunities. However, if the existing power supply mode is used, when the power level of a single electric arc furnace develops from tens to hundreds of megawatts, the additional electricity charges caused by the reactive power loss on the load side, the capacity of special transformers and the difficulty of manufacturing, the volume of the power quality compensation device on the system side, the occupation Both the area and the difficulty of control will increa...

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Problems solved by technology

[0006] In addition, for the control-protection system of the AC electric arc furnace power supply system, the existing power supply system fails to fully coordinate the power electronic control and electrode mechanical control under various operations. The flexibility of the former has not been fully utilized, and there is a large room for optimization. The mode selection of the latter needs to be redesigned under the conditions of the participation of the former; and when the renewable energy-energy storage unit participates in the power supply process of high energy load represented by the AC electric arc furnace, it is necessary to take into account the hierarchical control of the cost of industrial electricity consumption Instructions are automatically generated

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