Complementarity model for load tap changing transformers in stability based OPF problem

The paper presents a stability optimal power flow (OPF) based problem that incorporates complementarity models for load tap changing transformers (LTCs). The complementarity formulation models the change of behavior of LTC controlled buses when the tap becomes blocked at one of its limits and the voltage level can no longer be regulated. The incorporation of proposed model in stability OPF based problem leads to a more accurate estimation of the maximum or critical loading level.