Analysis Of Short-net Electrical Parameters And Application Of Compensating Methods In Arc Furnace System

With the rapid development of ferroalloy enterprise, the EAF has been widely applied. However, the EAF is a high energy consumption, nonlinear load which increases not only enterprise's financial burden but also the harm of harmonics and reactive currents in a power system, therefore, the question of the development of ferroalloy enterprise must be faced and needed to solve is the reducing energy consumption and the enhancement of the quality of electric energy in power supply system. This paper is sponsored by a project of Jilin ferroalloy works' comprehensive energy saving for EAF. It takes 20T EAF as concrete study object, proposes a EAF synthetical compensation method which compensates reactive power by static var compensator and administers harmonics by hybrid filter.First, this paper introduces the working principle of EAF and the operating characteristics of short net system, analysis active and reactive power, voltage, harmonics and distribution of other major power parameters in short net system detailedly, then a serious problem which is there are big reactive power consumption and high harmonic in EAF is found,so the key of energy saving for EAF is reactive power compensation and harmonic pollution control.Second, the characteristics and classification of static var compensator are introduced, and the basic principles and characteristics of TCR static var compensator are in a deep study, based on the working characteristic of EAF, TCR+FC static var compensator is adopted to compensate reactive power; The characteristics and the lack of harmonic control of active power filter and passive filter is summarized, a hybrid filter which is the combination of active power filter and passive filter is proposed.the hybrid filter overcome the disadvantage of high cost of active power filter and poor dynamic performance of Passive Filter, so it is more suitable for harmonic control in electric furnace.Third, Mallat algorithm based on wavelet transform is adopted by studying the detection strategies of reactive current and harmonic current, this algorithm completes a real-time and accurate detection for short net current signal, and it is more suitable for EAF load that its power parameters transient change is large.Finally, based on taking EAF's actual working condition and the distribution of power parameters of short net system into account, a overall compensation package is designed. and all component elements of this design are simulated by MATLAB simulation software. The simulation results show the correctness and the affectivity of the proposed design, and provide theoretical basis for application of EAF in short net.