Active Damping Across Voltage Levels for Harmonic Resonance Suppression in High Voltage Systems

The extensive integration of power electronic devices into power grid has led to increasingly frequent harmonic resonance issues, posing challenges for the secure and steady operation of new-type power systems. Existing active damping methods struggle to effectively address harmonic resonance problems in high-voltage levels. To address this issue, this paper puts forward a harmonic resonance suppression method for high-voltage systems based on active damping across voltage levels. The method installs an RC-type active damping device at the low-voltage terminal of the step-down transformer. According to the damping value required for system harmonic resonance suppression, the model of the step-down transformer is determined. And the virtual impedance parameters for active damping device are designed based on the parameters of the selected transformer. Finally, simulations are performed to verify the effectiveness of the proposed method. The results show that, under different simulation conditions, the suppression rates for the 5th, 7th, and 11th harmonic resonances reach 63.5%, 82%, and 76.9% respectively. It has a good suppression effect and realizes active damping across voltage levels for harmonic resonance suppression.