Modeling and analysis of naturally saturated reactors in optimal power flow studies

The daily variation of power system loading, increasing demand for electrical energy and contingencies may lead to poor voltage profiles of the system. Among several voltage control means, an Static VAr Compensator (SVC) based on Naturally Saturated Reactors (NSR) can be used to improve the voltage level at a given bus by the injection or absorption of reactive power. Furthermore, Optimal Power Flow (OPF) is a well known computational tool to calculate the optimal control adjustments. However, although several Flexible AC Transmission Systems (FACTS) devices have been modeled into OPF programs, the modeling of NSR has received little or no attention so far. Thus, the aim of this paper is to model an SVC based on NSR into an OPF program, and then to study the improvements on the system voltage profile due to the optimal control of this equipment.