The dual-loop control scheme of the electric arc furnace short circuit compensation implemented on the harmonic current soft survey

The random of condition changes in arc furnace and the fluctuation of electrode discharge arcing which bring serious problems, such as the heavy harmonic current and the low power factor, to short net. In this paper, a measuring method based on current decomposition and frequency transformation is proposed. Without additional hardware and complex operations such as conventional coordinate transformation, the testing of fundamental current, harmonic current and power factor are better received. Also, double closed-loop control system is designed which takes power factor as control objective and integrates reactive power compensation and harmonic suppression. The simulation and test show that the feasibility of the current prediction methods and the compensation control law are better verified. The harmonic current can be effectively reduced and power factor can be increased to more than 0.85. So it has obvious energy saving effect and provides a reference model to other electric power conversion equipment for harmonic prediction and reactive power compensation.