An optimal strategy against voltage collapse

An optimal strategy is presented to offer a preliminary solution to the growing concern of voltage collapse. The optimal strategy will maximize the power transfer within a given system while minimizing the necessary amount of shunt reactive power (VAr) support before voltage collapse is encountered. The strategy is based on the coordination of a locally parameterized continuation technique with an optimization scheme to the power flow problem. A continuation power flow program is first developed to overcome the singularity condition at the critical point. By taking advantage of the sensitivity information obtained from the continuation technique at each load level, weak load buses that have large differential change in voltage magnitude for a given differential change in load parameter are selected as the shunt VAr injection sites. An optimization scheme then follows to achieve the minimum amount of VAr based on specified system constraints. A simple 2-bus system which involves one generator and one load bus is first chosen to demonstrate the characteristics of the strategy. A 16-bus system is used to test its capability for a multibus system