No abstract

This article considers the mode of excitation of sub harmonic oscillations of the third order in a three-phase circuit consisting of active, capacitive and inductive elements having a common magnetic bond, which are analogous to the power line "line -unloaded transformer".Equations of motion are derived from the method of averaging with the corresponding phases.From the condition of the existence of the periodic solution, phase relations are determined that are different from the phase ratios for three-phase circuits with group Ferro magnetic elements. In the stationary mode, the conditions of excitation, the scope of existence, the dependence of the output values on the parameters of the circuit and the applied effect are determined.