Voltage stability preventive control using a new voltage stability index

Effective voltage control schemes have been brought to attention in a considerable number of studies, as power system loads are located farther away from power plants and reactive power losses have tended to increase due to the heavier power flow with high load growth and long distance transmission. In this paper, we propose on-line voltage stability preventive control. In order to simulate contingency analysis efficiently, we propose pre-contingency analysis, which is ranked by a new voltage stability index VIPIt. The VIPIt is based on the conventional index VIPI and it is used for assessing the effect on voltage stability in different generators as well.