Effects of FACTS controllers on small-signal voltage stability

This paper analyzes the effects of flexible AC transmission system (FACTS) controllers on the small signal voltage stability of a power system with an infinite bus supplying a load through a transmission line, while taking into account the static load and dynamic load simultaneously. It is shown that the small signal stability region is greatly enlarged by FACTS controllers, and the power system can even stably operate within a certain part of the lower portion of the system P-V curve. The paper also studies the potential influence of possible factors on the voltage stability region and the dynamic transition of the system.