Inadequate voltage control in the assessment of voltage stability conditions

Inadequate voltage control occurs when the controlling variable and controlled voltage of a control device are inversely related (i.e., not related in the usual way), potentially adversely affecting the system voltage level. This special situation can be identified by analyzing the elements of a sensitivity matrix constructed to show the relationship between the system control variables. Analysis of these elements not only allows the adequacy or otherwise of voltage control actions to be determined, but also helps to identify any conflict between controls that could, if not addressed, limit the possibilities for voltage control in the system. Furthermore, once the problem of the inadequacy of voltage control actions for a particular operating point has been identified, its impact on voltage stability conditions can be determined by calculating assessment indexes.