Experimental graphs of voltages and currents recorded for U = 100 V, time t = 500 ms and capacitance C = 5 ÷ 75 nF. The earth fault event results in a steady-state voltage with a maximum value of approximately √2 100 V during the fault. Due to the saturation of the transformer cores, rapidly damped currents with peak values of up to about 50 A flow in the primary windings of the voltage transformers. The value of capacitance practically does not affect the values and shapes of voltages and currents during a fault, but outside of some range the ferroresonance is not sustained.

See also: https://www.e-magnetica.pl/doku.php/file/tarko_et_al_ferrroesonance_damped_png

The images were copied from (and slightly modified):

• Tarko, R.; Nowak, W.; Gajdzica, J.; Czapp, S. Analysis of Ferroresonance Mitigation Effectiveness in Auxiliary Power Systems of High-Voltage Substations. Energies 2024, 17, 2423. https://doi.org/10.3390/en17102423

tarko_et_al_ferroresonance_examples.png