Abstract—Ferroresonance is a complex electrical phenomenon, which can cause overvoltages in the electrical power system and endangers the system reliability and continuous safe operating. This paper studies the effect of linear and nonlinear core losses on the chaotic ferroresonance in a voltage transformer. For confirmation this aspect simulation has been done on a one phase voltage transformer rated 100VA, 275kV. The magnetization characteristic of the transformer is modeled by a single-value two-term polynomial with q=7. The simulation results reveal that considering the nonlinear core losses on the voltage transformer, exhibits a great effect on ferroresonance overvoltages. Significant effect on the onset of chaos, the range of parameter values that may lead to chaos along with ferroresonance voltages has been obtained and presented.

Index Terms—Nonlinear core losses effect, chaos, bifurcation, ferroresonance, voltage transformers, linear core loss.

Hamid Radmanesh and Jafar Khalilpour are with the Electrical Engineering Department, Aeronautical University of Science& Technology, Tehran, IRAN (e-mail: Hamid.radmanesh@aut.ac.ir,J_khalilpour@yahoo.com).
Mehrdad Rostami is with Electrical Engineering Department, Shahed University, End of Khalij-e-Fars High way, In front of Imam Khomeini hollyshrine, Tehran-1417953836 , IRAN (e-mail: rostami@shahed.ac.ir).