Evaluation of load shedding to prevent dynamic voltage instability based on extended fuzzy reasoning

A reliable load-shedding approach, which makes use of a knowledge base and extended fuzzy reasoning, is proposed to arrest dynamic voltage insecurity following a disturbance. Irrespective of the nature of the dynamic voltage instability, the location and required amount of load shedding among load control buses can be promptly presented in realtime to the system operators. In the development of this scheme, fuzzy indicators for all load control buses are firstly established and then correlated with the real load-shedding amounts decided during the off-line simulation study. The load-shedding amount for previously unseen operating cases at each load control bus can be conservatively predicted according to the zone within which the fuzzy indicator falls.