The latest development and existing problems of power system security feature selection are briefly introduced. An online distributed security feature selection method is proposed. The method is based on power system security feature grouping by correlation and adapts to the big data in power system operation

and it could online discover critical features for power system security. First

a power system security feature selection method for a single compute node is discussed. Then a distributed method based on feature grouping is proposed. As the feature grouping method has an important influence on the selection results

a strategy based on power system security feature grouping by correlation is put forward to make correlation of features within the same group larger while the correlation of features among different groups smaller. This distributed security feature selection method is well applied in IEEE 9-bus system and Guangdong power system for its practicality and effectiveness

which could quickly find out the weak spots in power system operation and accurately help operators grasp the critical features for power system security. Compared with traditional methods

this method performs well for its compute accuracy and speed.