In order to prevent cascading failures and large-scale blackouts

it is of great significance to monitor the operating state changes of power grids. In view of the limitations of the fuzzy set theory

an intuitionistic fuzzy analytic hierarchy process(IFAHP)based method for evaluating the operating states is proposed. Firstly

the hierarchy model for assessing operating states is developed. Then

the complementary judgment matrices using intuitionistic fuzzy numbers is built to calculate the weight coefficient taking into account both the degree of membership

nonmembership and indeterminacy. Thirdly

this paper introduces a dynamic adjustment strategy for the degree of indeterminacy

which improves the differentiation degree of evaluation. Finally

the score function of intuitionistic fuzzy numbers is defined. Based on this function

a method for ranking evaluation indices is presented. Simulations are conducted in a certain power grid at different load levels and in different operation modes. Results show that the proposed model can effectively and flexibly identify the operation states of the power grid.