NONLINEAR DYNAMICS AND SWITCHING TIME BIFURCATIONS OF A THYRISTOR CONTROLLED REACTOR CIRCUIT

We study a thyristor controlled reactor circuit used for static VAR co ntrol of utility electric power systems. The circuit exhibits switchin g times which jump or bifurcate as fold or transcritical bifurcations. We study the nonlinear dynamics of the circuit using a Poincare map a nd demonstrate that the Poincare map has discontinuities and is not in vertible. The circuit has multiple attractors. Moreover, the basin bou ndary separating the basins of attraction intersects with the Poincare map discontinuities. These novel properties illustrate some of the ba sic features of dynamical systems theory for thyristor switching circu its.