Voltage Distribution Factors for Post Contingency Local Load Relief Warning

This paper presents a methodology to calculate Voltage Distribution Factors (V-DFAX) for post-contingency low-voltage violations. For low-voltage violations which have no controlling action besides post-contingency load-shedding, PJM and their Transmission Owerns (TOs) develop Post-Contingency Local Load Relief Warning (PCCLRW) plans which are only implmented in the unlikely event the contingency occurs in realtime operations. Load shedding Distribution Factors (DFAX) for thermal violations are calculated within the Energy Management System (EMS). However, due to the non-linear relationship between load and voltage, a gap exists for V-DFAX. The proposed methodology is to address this gap by using graph theory and AC power flow solutions. The methodology and its implementation are presented in the context of PJM's power grid.