Search for network parameters preventing ferroresonance occurrence

Application of the continuation and bifurcation method for studying the influence of network parameter values (e.g. source voltage, network capacitance or damping resistance loading the broken delta of voltage transformers (VT) tertiary windings) on network stability is described in the article. It is possible to estimate in this way sensitivity of the network to ferroresonance occurrence after a fault such as breaker switching or ground short-circuit. The advantages and limitations of the method are given. The examples of the method used for 6 kV auxiliary substation in the power plant and for 110 kV networks are presented. The ferroresonance may be a result of the interaction between the VT inductance and the network capacitance or grading capacitance mounted in the breaker. The results of field measurements and calculations using the XPPAUT continuation package and simulations using the EMTP program are shown.