Preventive Voltage Rescheduling

Overview
PVR adjusts voltage on generators within the control region of the load pocket to obtain a dynamic approximation solution by increasing the reactive reserves to a sufficient level for the contingency so that the solution is found. Conventional P-V and V-Q methods do not define loadpockets correctly which make them incapable of predicting the control region used in Preventive Voltage Rescheduling Control.

Comprehensive
  • Voltage Rescheduling can obtain solutions for the dynamic approximation solution process for generally half the contingencies that have no loadflow solution; Preventive Load Shedding is able to obtain solutions generally for the remainder of the contingencies
Diagnostic
  • Voltage rescheduling is performed in subnetworks of the control region for a contingency based on a priority that reflects its contribution to initiation and propagation of cascading voltage instability
  • Voltage rescheduling is performed on generators in the problematic subnetworks for most contingencies
Structural
  • PVR is able to detect when Voltage Rescheduling is required in more than one subnetwork that lies in the Control Region of a loadpocket; This is needed because problematic loadpockets often exploit more than one structural problem