Restraining Of Arc Furnace Harmonic Current And Improvement Of Its Electric Power System

With the development of the steel making technology, more and more arc furnace invest to the industry, its capacity also become more bigger. Arc furnace will produce abnormal production high secondary harmonic waves and voltage flashing changes, unbalance of three phases, low power factor etc unfavorable influences, and they are generally passing over the quality of electric energy which concerns to each item of index and the limit value of the national standard. The research base on the real background of Jin Sha steel mill ' arc furnace electric system, the problems of mathematical model of the arc furnace electric power system, harmonic analysis are researched and some measures about restraining arc furnace harmonic of Jin Sha steel mill are put forward .This paper introduced the generation of the arc furnace harmonic and its harmful influence. The quality of electric energy which concerns to each item of index and the limit value of the national standard and way to restrain are involved. On the physical mechanism of alternating- current arc, the circuit model of alternating arc is put forward in this paper, and engineering estimating method of the arc parameters is given .The availability that model reflect external characteristic curve of alternating arc is verified through simulation, and then the state equation of arc furnace electric system is studied. Take two methods to detect the data of the arc furnace harmonic , and analysis it. On this basis, makes some preliminary investigations for passive filter basic principle. According to the national standard, designed the reactive power filter project in keeping with that system, and simulated. In the end, the other unfavorable influences are analyzed. The methods about suppression the voltage flashing changes, unbalance of three phases, low power factor are put forward. Analyzed in details the main composition, basic principles and control system. Base on the theory of the instantaneous reactive power in three-phase circuits, proposed a way to detect the SVC signal. Carried on the first step design. Discussed the main composition, basic principles of the active power filter, it makes a conclusion of the function in the arc furnace system.The design has already been making use of in the actual system of Jin Sha steel mill, and received the expectation result. It proved that the project has good economy...