Wideband Frequency Harmonic Resonance Analysis and Suppression Method of Power Grid

The distributed capacitances of the high-voltage transmission lines are easily coupled with the inductive components in the power grid to generate harmonic resonances, which amplifies the voltage and current harmonics and reduces the power quality of the power grid. Taking a 220kV substation system in Guangxi as an example, this paper analyzes the mechanism of harmonic resonance of power grid by establishing grid impedance equivalent model and singular value analysis method firstly. Then a harmonic suppression method based on SiC MOSFET is proposed. Correctness of the theoretical analysis of harmonic resonance and effectiveness of the harmonic suppression method are verified by simulations.