Research on Suppression Methods for Ferromagnetic Resonance in Low-Frequency Voltage Transformers

Flexible Low-Frequency Transmission (FLFT) offers advantages in reducing reactive power and lowering costs but faces potential system instability due to ferromagnetic resonance in electromagnetic voltage transformers (PTs). This study proposes optimizing PT core and high-voltage winding designs to suppress resonance. By analyzing resonance conditions, selecting appropriate magnetic flux density, refining lamination processes, and optimizing winding structures, the study achieves effective suppression. Simulations and tests on a 220 kV prototype demonstrate that increasing winding turns and adopting a tower-shaped coil design reduce resonance and enhance capacitance. Results confirm improved PT stability under varied GIS conditions, offering a practical design optimization for FLFT systems.