Electric Arc Furnace Power Supply System Integrated Compensation Stady

In electric power systems, power quality, security, reliability and economy operation is the most fundamental problem. In recent years, With the rapid development of metallurgical industry, With a large number of electric arc furnace(EAF) load constantly input, EAF during normal power production will result in high harmonic, voltage flicker, voltage fluctuation, three-phase voltage and current unbalance, power factor low effects and power quality exceeds national standards.At present, main measures of EAF grid disturbance is a static var generator (SVG), static var compensator (SVC) and active filter (APF). The establishment of an accurate EAF model is first Conditions for assessment of power quality problems. Firstly, in the MATLAB environment, EAF power supply system model is established, which based Professor Xiao Xiangning raising three-phase non-linear model. A large number of EAF generated high-order harmonic, APF inject to grid with amplitude equal and the opposite phase current harmonic the power with controllable power semiconductor devices. The total harmonic current power supply is zero, which achieve real-time compensation purpose of harmonic currents.Then, apply SVG on EAF for reactive power compensation, use instantaneous reactive power theory, detect instantaneous reactive current of electric arc furnace load, PWM control techniques track based current waveform whit this feedback control, So that SVG can generate the required reactive current. The simulation results show that this method has not only achieved a three-phase unbalanced load balancing and improved the power factor, but also has a good compensation effect.Finally, as electric arc furnace of 1st Heavy Machinery for example, the parameters of the SVC has been designed, including the firing angle setting, the parameters design of passive filter FC and SVC compensation capacity. And it is applied to EAF power supply system. SVC is the most widely used for EAF compensating device at home and abroad. In this paper, the TCR type SVC is used, which uses silicon-controlled valve to control the linear reactor to realize fast continuous reactive power regulation. It has an important role in a response time fast, reliable, non-level compensation, cheap, high power factor, inhibit asymmetric load, Thus which is used in power system the most widely.