VOLTAGE COLLAPSE AND CONTROL ACTIONS - EFFECTS AND LIMITATIONS

This paper focuses on control actions determination for voltage collap se prevention. Sensitivity matrices are proposed based on the knowledg e of the critical bus. By critical bus one means that bus whose state variables vary at most at the voltage collapse point. A tangent vector is used to identify the critical bus, and its behavior as a function of load increase is also investigated and compared with other indices previously proposed. It is shown that generator control actions may no t work to increase voltage collapse margin, whereas local control acti ons may produce better results. The tests are carried out in the IEEE- 300 bus test system, with and without reactive power limits considerat ion.