Blocking reactive power generation as a voltage control measure

This paper proposes a method to block voltage regulator action with the meaning to enlarge a system load margin. Local control actions seem to be effective for this purpose, but are dependent on the existence of local sources. On the other hand, sharing the voltage control with the help of multiple machines-control provide good results, which is associated to a secondary voltage control strategy. Voltage collapse problems, when triggered by successive load increases, may be flagged by some important signals. In this paper, the reactive power generation/voltage level relationship is monitored, so the reactive power is blocked in an upper level prior to voltage collapse occurrence. A small test system is employed to show the idea and others IEEE systems are used to test the methodology.