Research on High-Voltage and Large-Capacity Active Power Filter for Intermediate Frequency Induction Furnace

摘要

In this paper, by analyzing the characteristics of nonlinear load intermediate frequency induction furnace in steelworks, a harmonic suppression scheme of high-voltage and large-capacity series hybrid APF(SHAPF) was proposed. Based on the principle of magnetic flux compensation, the SHAPF can make the primary side of transformer present short circuit to the fundamental approximately and show high impedance to the harmonic by detecting the fundamental circuit and the selected harmonic currents, which play a role of harmonic isolator. Selected harmonics injection makes the frequency band of control system better handled, which reduces capacity effectively. Additionally, the SHAPF can isolate the background voltage harmonics. Finally, the experiment proves that the SHAPF can be applied to the intermediate frequency induction furnace, and reduce the capacity of the device and isolate the background harmonics.