This paper investigates the use of the QV and PV curves in the planning scenario, when some system reinforcements and contingency screening are analyzed. The idea is to employ the continuation method to obtain the system load margin and the QV curve to calculate the reactive power reserve associated with each bus. Combining these approaches enables one to identify the system critical area, the actual operating conditions, the most severe contingencies and the most important reinforcements. The methodology proposed may provide important signals to system planners, since the planning is focused under the voltage security point of view. The ideas are tested with the help of some academic systems and two real (a Brazilians and a Paraguayan) systems with all the system limits considered.
Highlights
► We use PV and QV curves as computational tools for planning scenarios. ► We discuss the effects in the critical bus identification by both approaches. ► We show that QV curve may show the robustness of a bus with respect to reactive power support. ► We apply the methodology to contingency screening