FUZZY-REASONING FOR KNOWLEDGE-BASED ASSESSMENT OF DYNAMIC VOLTAGE SECURITY

An easy-to-use knowledge-based fuzzy approach is proposed to evaluate the dynamic voltage security including both voltage collapse and unacc eptable voltage profiles following disturbances. The dynamic voltage-s tability behaviour of the power system, however complex and nonlinear in nature, is simply mapped into a fuzzy severity index by means of ap proximate fuzzy reasoning and a series of fuzzy calculus. In addition to providing a mere two-region demarcation, the fuzzy severity index c an also generally give a relative severity indication to discriminate between various post-disturbance system states. A systematic methodolo gy for initial fuzzy-parameter setting and fuzzy-variable selection is also presented and discussed.