A practical corrective control strategy to mitigate voltage collapse

To restore post-contingency system solvability, a new minimum load shedding approach is proposed. Using the damped Newton-Raphson methed, the system minimum mismatch function is calculated to identify the weakest bus and determine the most effective load shedding strategy. The weakest bus voltage of minimum mismatch solution is set as known parameter and the scaling load coefficient of the shedding load bus as unknown in the power flow equations, then solve the modified mismatch function to estimate the minimum amount of load shedding. The amount can be refined by a traditional PV curve method. The proposed approach is illustrated with the New-England 39-bus system and the IEEE30-bus system. The results show that the approach is very simple and efficient and is easy to be implemented.